As a blanket statement? No, we don't. Two reasons why:

1. "Make their own decision" is an extremely inaccurate phrasing. Unsophisticated investors do not have enough information to properly evaluate a decision, and are therefore unduly influenced by companies wanting to take advantage of them.

2. There's a cost to society from people who take risks that have negative expected value and then expect society to help them. Of course, society could just refuse to help them, but find that society works better when certain support structures (e.g., the ability to discharge debts in bankruptcy) exist, and it's very hard to distinguish people who "really" need the support structure and those whose petard is their own. If social pressure or regulation can deter people from taking these risks, that's slightly unfortunate for the person who would have won the gamble, but very advantageous to the health of society as a whole.

Both reasons are also why outright gambling is regulated, why publicly-traded companies are subject to financial regulation, why we don't let people "make their own decisions" about raw milk, untested drugs, aircraft, etc. - there are strong incentives for the people selling you that product to lie to you by omission in the hope of influencing your decision to be profitable to them.