Why hoard stardust?

I hoard stardust (over 800,000 right now). I have 6 mon that I max out (two 91% Vapes, a 93% Venusaur VW/SB, a 89% Lapras FB/B and a perfect Arcaine FF/FB) and they are the only ones I spend dust on. In one word I would say it's perfectionism, always thinking that a mon isn't good enough to power up and that I'm going to find a better one and want to have plenty of dust available when I find those better mons.

Freedom of action and a slight stroke of perfectionism, is my motivation for hoarding. Knowing that I could catch that 100% Dratini or Bulbasaur during the next 5 minutes and evolve it with the perfect moveset, is why I don't want to sit at a mere 5k stardust if such event should happen.

I caught a lvl 14 Dragonite with 96% IVs wild 2 weeks ago, and having the freedom to immediately spend the 99k dust needed to bring him to lvl 30 made it all worth the hoarding for me. The same goes for hoarding rare candy.

With most species I would rather evolve a ~70% IV pokemon at lvl 30 than evolving a 90% lvl 20 from an egg and then spending 70k stardust to bring him up to speed. That's how I've ended up with a fairly strong base of pokemon without emptying my huge mountain of roughly one million stardust.

For me, stardust is only spent on high IV pokemons with great movesets that I know will be competitive and useful in some way or another for a long time to come. High CP mons with good defensive movesets or generalist/grass attackers to counter the hordes of Vaporeons in gyms are the only ones I have powered up until now. And I'm having a blast.

Things change. You catch something new, Niantic does a re-balance .... It is nice to have resources on hand to respond quickly. You can respond playing hand-to-mouth fashion. It just takes longer.

Why doesn't Warren Buffet or Bill Gates spend everything they make?

I've mis-spend so much of my stardust, (the night before the big buff/nerf, I spent a bunch of dust on mons that got nerved). Now I'm way more careful.
Once you start being careful, then dust builds up fast.
I will only spent it on my high cp mons to drop in gyms.
My best attacking mons range from 1k to 3k. I like to prestige gyms so I can't spend dust on my attacking mons. I need to keep them low.

I personally only spend dust on 85%IV or more mons with the perfect moveset that I really want to use and love to, no matter what, even if they not have the biggest CP or power.

For example, a part from 2 Dragonites, Snorlax, 2 vapes (1 defense 1 offense) and a perfect Gyarados I have powered up to the max of my level (34) a Raichu with 90%IV, a Charizard and a perfect IV Blastoise, because I love them and I use them every time I can.

I won't save a milion stardust because I think one of the points of enjoying the game is powering up your mons and use them in battle, but I made my own limit at 350k, so I have this amount always saved in case I hatch the good Lapras, Dratini or Snorlax or gen2/legendaries come.

Similar to the others here, I don't really hoard dust, just that I don't want to power up mons that aren't going to sit in gyms when other people in my area are mostly powering up 90%+ mons or simply have more/better mons. I'm a free player so you can assume most level 30 people will have accumulated about 1 million - 1.5 million in dust around that time.

Using 75k-120k (Lvl 20 - Lvl 1) in dust for lower IV mons will remove that from your inventory and since you can really only max out 10-15 mons initially, it's safer to wait for higher IVs assuming you want to be in gyms to begin with.

At least until you start hitting the exp wall, you probably won't have enough dust to power up everything since you level relatively quick from 1-30.

It's great to be able to get a good hatch and instantly (or near instant if you don't have enough candies) to max it for your level and have it instantly usable.

When gyms are stacked with only Dragonite, Snorlax, Gyarados or Rhydon (and some Vaps), if you start powering up random mons with 50% IVs, you simply won't have enough CP to have a spot in the gym at all (at least not in my area which is mostly 2600/2700-3000).

Like others, I don't blow dust anymore (learned the hard way) but I'm also not afraid to spend it on Pokemon I love using. What's the point if you're not having fun?

My most recent were an 89% wing/blast charizard, 89% tshock/TBolt jolt, 96% shadow claw/sludge gengar, and 93% psycho cut/psychic alakazam

Are they all necessary? Nah. But I enjoy using a range of Pokemon including my favorites rather than a team of 6 vapes and dragonites

But I keep a 200k dust floor, in case a situation (rebalance,new catch, etc) arises where I want to have an immediate supply

I have around 380,000 dust and only power up Pokemon that I use in battle or on Gyms:
2 Dragonites
3 Snorlaxes
2 Rhydons
Vapes, Flareons, and Jolts
2 Gyarados
1 Golem, 1 Lapras, 1 Aracanine, 2 Exxes, 1 Cloyster,
2 Magnetons, 1 Machamp, 1 Poliwrath.
I could play with 50 Pokemon but currently have 342.

I spend mine like water, but I like using a range of defenders and attackers. For me the lack of decent candy holds back powering up more than any lack of stardust (no wild Snorlax/Lapras/Chansey spotted in my area by any players I've spoken to (I'm lv33) and Dratini are rare). I normally have about 10000 in reserve, but that's it.

Well, you'll hear many people hoard Stardust and Candy for "just in case" or for "when Gen 2 is released".

I personally spend it as soon as I have it (mostly). To me, this is a game and I want to enjoy it now... I enjoy powering up my favorite mons, my favorite attackers and my favorite defenders. I'm pretty creative at finding new ways to spend it :-) I also don't have any problems grinding out more if needed (I can build ~200k stardust in about a week).

If other folks want to hoard it, it's their prerogative. Just want to make sure everyone remembers that this is a game played for enjoyment and you shouldn't deny yourself enjoyment hoping for something magical to come in the future.

For example, some of my friends have been hoarding "Gen 2 candy" since October. They missed out on some serious XP through evolutions during the Thanksgiving event. We have no idea when we will actually get Crobat, Politoed, Slowking, Kingdra, Bellosom, etc.