So I know some people here are stoked for a third power to some of the villians, or major buffs for characters. However, do not forget, MPQ is free to play.
So what does that mean? That means that their revenue is not a consistent stream based on players, but based on a few donations here and there, and a massive amount from whales (People who spend hundreds or thousands of dollars). That means that while you want a fun game, (and they do!), the reality is, a lot of their development decisions have to be concerned with return on investment if they want to stay in business.
So lets look at three things the community wants: 3rd power for villians, buffing old characters, and nerfing overpowered characters
1. 3rd power for villians
The old 2 star villians are very old characters by this point, and as such, many people already have them. Where does d3 make money on this? They could either spend the development budget and time on a 3 color covers that no one has, and have people buy covers, packs, and iso...or sell far less by rebalancing a character and adding a 3rd cover. Some may say, "But Daken!" Well, they released a NEW Daken, and rebuffed the old one. If they're going to rebalance, its probably going to be while releasing a lazy version as well. Otherwise, I can't see the business sense in it. After all, no one is going to leave if they don't add third covers.
2. Buffing old characters
Again, how the game makes its money is people buying iso, cover packs, character covers, and shields. Where is there money in buffing old characters a large percentage of the population has? Again, this is usually a poor return on investment. You might say, "But Hawkeye!" One abiliity was changed, and I think this was to help people in the two's transition. You want to keep people through the 2's so that way they'll play for 3's, and spend money on the game. This is also why X-Force was buffed. He's incredibly hard to get, and a powerful 4 like fury probably gained them a bit more revenue. I'm sure the X-Force buff caused more people to buy covers, and net D3 some well earned cash.
3. Nerfing overpowered characters
I've seen this community, and people who have their overpowered characters are weak little whiners who have their ego caught up in being overpowered. They'll throw an F'n FIT. When the Rag nerf hit, people downvoted the game to oblivion, flooded asking for refunds, and generally behaved WORSE than children. So where is the profit for D3? Unless overpowered characters are ACTIVELY harming the game, causing people to quit, or causing people to NOT buy new characters etc., then there is no financial incentive for D3 to do so.
If anything, Sentry is a gold mine. He allows shield hopping up to the 1300's and beyond. People are popping money on shields like mad. Why would D3 shoot their own foot? Until Sentry stops people from buying shields or anything else, they'll ride that money train for as long as possible.
TLDR: Remember guys, this is a free to play game, not a monthly service. Always expect D3 to make the game fun, but always in the direction of them making the most money in return for their time investment. Also, I love this game, and do not think they are money grubbing greedy bastards. =D