(That's not to say that their help doesn't tend to have adverse side effects, just that the IMF isn't generally doing anything to your economy if you have stability around to destroy.)
"They're not so bad. They only exploit the desperate."
That the description of them destroying stability has a false premise. I mean, how much more explicit could be?
If you are looking for a secret ulterior motive, the difficulty is because there isn’t one.
More seriously, that's not what GP meant at all. GP's point is that IMF usually steps in only after a country managed to paint itself into a financial corner - at this point there's no "nice" solution any more, and you're guaranteed to deal with mass unemployment, people losing their life savings, inflation, and so on.
Of course the debate is ongoing whether IMF's proposed solutions are actually in the best interest of the countries on the receiving end, but you know, if they don't like the deal these countries can always refuse it.