May be they are looking for high returns on their investments even bitcoin giving consistent returns in longterm the percentage is small when compared with trending coins.
Well, we people won't just invest for nothing but we invest for a profit and we like it even more if we can also earn tons of profit. Saying that BTC giving consistent returns for the long-term is actually better than what alts can provide normally even if that return is what we can say only small.
The truth is that there is no such consistency in crypto due to their volatile nature but it is true that BTC can provide good profits sometimes in the long-term, while many alts especially the trending ones don't usually last long. Even with that, BTC can still win over them. New alts can get trendy and that can give the investor a quick gain. This is the reason on why someone will be interested on them. Other than that, alts do also have a different use case than in Bitcoin.
You nailed it. People are trying to make their fortune from altcoin. though it's rarely happening, but it can give you a jackpot if you can find a legit token. Also, read some stories about people who became billionaires. They made their fortune by investing in a meme token.
'Make a fortune' can also mean small amount and this is highly possible in investing in altcoin. There are still good alts too, so earning bigger profits is possible as well. Legit token is only legit but it does not mean that it is now going to be the next BTC. I won't say that those one-hit wonder cryptos are not legit because they still manage to pumped-up and then if we are fortunate to invest with them we can also have an epic moment.