With regards to treating investing like gambling, there's no real problem with that. There's definitely a market for it, and it's why /r/Wallstreetbets exists.
There's a big problem with that, because marketing gambling to Americans is often illegal. Do people remember the poker boom and Pokerstars getting destroyed? https://en.wikipedia.org/wiki/United_States_v._Scheinberg
Like drugs, criminalisation outright creates problems. Like tobacco, allowing people to market addictions with serious adverse effects can't be allowed to continue indefinitely. This stuff should end up like tobacco in some countries: legal to sell, but not to market it, you have to ask for it.
There are also markets (pretty large ones too) for cocaine and hookers and human trafficking.
There is a difference between treating investment like gambling and teaching and encouraging new investors how to take unnecessary risks.
In fact, if not for the blatant hypocrisy of them doing this under this mission statement “democratizing finance”, I may be ok with how predatory they are.