It's not about whether they're smart or not - it's that a multimillionaire can lose a bunch of money on a private company and not be out their retirement savings. That's not nearly as true for the typical middle class person.
It's not designed to prevent 'ordinary' people from sharing in investment profits, it's designed to protect the public purse from having to support millions of people that lost their savings due to unwise investments.
If it's the latter, then there are probably far more creative ways you could help their situation than contributing a few thousand dollars.