I think its the expansion of discussion of games on the internet. If you play a game in an isolated setting you have to count on you seeing the bug to know it exists, and even then some bugs are obvious as bugs. When people get out and discuss them online their existence becomes obvious.
In regards to your most poignant point about levels I gotta say part of me really sees where you're coming from.
Getting back into WoW recently the game lets you go through levels much more quickly so that you can get new stuff for your class, but by leveling more quickly you are left with content you can't really experience as it was meant to be because you've leveled to fast for it, so in the end the restriction of levels actually makes it so less content is available to you at any one time. World of Warcraft is at a point right now where it has the most stuff in it then any point in history, but until the next expansion comes out max level players have the least amount of stuff they can do that matters to their characters ever. Levels do have a place in mmo's, but making them so rigidly tied to content and making the future progression of the game just raise the level cap makes it so an mmo is never actually growing, it's just getting longer and more frail.