Marvel's Avengers is adding more grind for some reason

Simon Cardy for IGN:

The dev team recently announced an XP rework that will make grinding hero levels a slower process than before.

It’s becoming clear that the game Crystal Dynamics believes they’re making is not the one that customers want. At no point in my time with the game did I wish the level grind was slower. The overwhelming number of in-game purchases, the disjointed, repetitive gameplay, and limited enemy types… those are the things that need fixing. Please start there.