Logic behind lures ?

I really dont like lures, my rarest pokemon obtained with a lure was a krabby, and there are pretty common. Beside that only rats, birds and eevees.

Lures are meant to encourage you to go out to places where a lot of other people are playing.

Personally, I think lures are sort of an outdated concept of the game at this point. There was a time where people set lures everywhere and congregated and caught pokes. Now unless you happen to be sitting somewhere like a restaurant for a while there's not much point to it. Though I think during events like the one going on right now they might spawn starters which is good!

It's really about being able to grind XP and stardust as fast as possible.

Putting up one lure isn't very impressive... In my opinion, you need at least 4 or 5 lures to make it worthwhile. Preferably 6 or more, and you can really grind away.

With 8 lures, and a lucky egg going, you will getting between 15,000-20,000 xp, 4,800 stardust, 48 pokestop spins of items, and 48 pokemon equaling 192 candies.

Heck even if only half of those are pidgeys, that's another 8,000xp of evolutions you could do.

There are some players that prefer to grind, level up and beef up their pokemon for gym battles. As of right now, I filled up my pokedex with the exception of the legendary pokemon, the regional exclusive ones, and one stupid MUK that I need to walk my grimer another stupid 117km to evolve...

Using lures doesn't mean you have to sit still. Level 40 players got there by finding spots with lots of stops luring them all up then doing laps around them to hatch eggs at the same time as catching.

the ultimate strategy for xp is find a place with at least 4 pokestops, lure them all, turn on an incense, use a lucky egg, walk around the pokestops and evolve pidgeys if you clear everything on the ground.

xp and dust
of course, mass evolving is the best way of expend lucky eggs