Something to keep in mind.
This Gym system isn't designed for us.
What I mean by that is... this new gym system isn't designed for Veterans who could already get themselves into just about any Gym they wanted to get into. Instead... it is designed for people like my wife... who has a handful of 1.3k CP pokemon and everything else she's got is much lower.
The old system was basically not a thing she could take part in at all without my help. With 2k+ pokemon in every gym she straight up would not be able to clear a gym with even 3 pokemon in it, much less 10. Prestiging would have been spectacularly difficult because she's only got her best 4 pokemon at a decent prestiging CP... she hasn't got our massive back stock of random hatch evolutions / furrets / whatever to use. Also Prestiging would land her the bottom slot in a gym... prime to get shaved out of it. Basically Gyms were impenetrable monoliths for her.
Now this new system...
Prestiging is gone and honestly... while I liked it, it was a system that was just straight up poorly designed. If there's an open slot in a friendly Gym... she can just put something in there and be fine. Also since CP doesn't decide the battling order, she's not going to just get shaved out. Also with the CP decay she's much MUCH more likely to find an enemy gym she can actually attack. Beyond all of that, the fact that you can spin and feed friendly pokemon means that even if she can't attack / add a pokemon to the gym, she can still use the things.
Is this system going to require more work for us veteran players? Sure... but having arguably the main system of the game be something that only hardcore veterans can get anything out of is a very VERY good way to have your game die.
Answers
I have no problem with the current setup. I think a few tweaks could bring it around.
One thing that you may be neglecting is that I doubt many low level players spend. If the system alienates too many players that do the game will be designed for no one since it won't exist. Not saying this system does that or anything.
Problem I see is gyms are a major time sink to bring down...if you are in an area with enough rivals that constantly feed berries, having to fight Blissey 4+ times and a Snorlax, a Chansey, Vap, Lapras is just a total time sink.
Your wife would've NEVER been able to clear the gyms now and it's even worst for you to tear down.
Clearing gyms just seem to take SO MUCH LONGER imo...Also, it's impossible to prevent gyms from being built up since getting 6 spots instantly makes a gym teardown so much more work.
At least with prestiging, you felt people had to "earn" their spot...and rewarded level...
Now, the gyms reward the last gym attacker since they can get coins the rest of the night before someone clears it again...
I disagree.
This morning I took down a gym inhabited by a 1800 Rhydon and a 1200 Blastoise. Whoever owned them had let them decay and my wife could have handled either of them. She may not have been able to clear it on her first attempt but as far as I know there's no bonus for clearing the whole gym so that doesn't matter.
Also on my way to work I saw some gyms with random 500 CP pokemon in them. Those she definitely could have fought.
Clearing low level gyms does take longer... but honestly it needed to. A fresh level 2 gym in the old system was a complete pushover. Meaning that players had very little incentive to actually y'know... take down bigger gyms because 10 coins wasn't worth battling that level 10 monstrosity for over an hour.
