That's not what I interpreted the parent as saying. He said

Investors are always looking for the next small thing that will make them big money.

Which I think my interpretation fits just fine - investors would like to put their money into something new that will become successful, that's how they make big money.

The word "ethical" has become heavily abused in discussions of AI over the past six months or so, IMO. It's frequently being used as a thought-terminating cliche, where people declare "such-and-such approach is how you do ethical AI" and then anyone who disagrees can be labelled as supporting "unethical" approaches. I try to avoid it as much as possible in these discussions. Instead, I prefer a utilitarian approach when evaluating these things. What results in the best outcome for the most number of people? What exactly is a "best outcome" anyway?

In the case of investment, I like a system where people put money into companies that are able to use that money to create new goods and services that didn't exist before. That outcome is what I call "progress." There are lots of tricky caveats, of course. Since it's hard to tell ahead of time what ideas will be successful and what won't, it's hard to come up with rules to prohibit scams while still allowing legitimate ideas have their chance. It's especially tricky because even failed ideas can still result in societal benefits if they get their chance to try. Very often the company that blazes a new trail ends up not being the company that successfully monetizes it in the long term, but we still needed that trailblazer to create the right conditions.

So yes, these "bubbles" have negative side effects. But they have positive ones too, and it's hard to disentangle those from each other.