Why do we play Maplestory?

Now I wonder if the guys who were developing this game at alpha were targeting this game to be as P2W as it is now.

Actually, the way MapleStory is written, it appears the original version was meant to be a peer-to-peer kind of system, with the server, if any, only being a database and/or largely transparent communication switchboard. Like a toy some college students wrote to play with each other.
Then someone must have said "this game is so cool, I bet a lot of other people would like to play it, maybe we can even make a bit of money", and the rest is history.
It didn't scale well at all.