MIT actually makes it harder for people to profit from their software than GPL, because the developer of GPL-licensed code has the exclusive right (by law, as author) to produce proprietary forks of that code; if the code's MIT'd, somebody else could fork, clone the proprietary features and add a few more (preferably going against the original program's general philosophy in doing so, to reduce the chances of those features being introduced into the original), aggressively market, and basically steal the whole project and its user base… then the developer's unemployed, the whole thing's proprietary and some unethical organisation is profiting off the work of another.

The “rolling release” model, where the latest version's proprietary but six months ago's version is libre, simply cannot be done with something like MIT unless you're willing to risk somebody else taking it all for themselves.