Tithing is common in most christian denominations, and is legally mandated (and automated) in several European countries via a "church tax" if you're officially registered as a member.
Even the 10% number is derived from the Bible (LEV. 27:30–34). There's nothing particularly nefarious about the Mormons here.
I don't have the moral fortitude to defend Mormonism as a religion, but based on the model of organized religion as a theocratic social insurance program (which it has been since, at least, Leviticus), your complaints don't seem entirely unreasonable:
> membership costs 10% of all you earn
10% is less than I currently pay into my state's social safety net programs.
> If you are in dire straights as a member and require assistance, the program is geared to get you off their assistance ASAP.
Shouldn't "returning people to self-sufficiency" be the goal of any social safety net? As far as I can tell, when you build classes of people whose lives are exclusively and indefinitely supported by welfare, things don't go well (especially when the people who fund the social welfare system get a bit strapped for cash).
The point is, they've amassed hundreds of billions or even trillions of dollars with this stingy pyramid scheme. The "social safety net" they offer is a joke. Enjoy your knitted blanket and can of baked beans.
The institution is only generous with their marketing budget (e.g. BYU, which is also run on a shoestring budget) or when they're on the receiving end of generosity.
The whole enterprise feeds on the exploitation of human souls for free labor.
It'd be nice if they looked outside themselves a little and invested their resources into efforts to help human-beings. Does "god" really only want them helping themselves?