Because the problem at the moment is there's a lot of scams than profitable altcoins right now that's the reason its hard to decide nor trust on which altcoins we are going since we don't know if their projects will continue to prosper and can able to give us good possible returns. That's why same for other people I usually go with bitcoin since from this coin I don't have any worries to experience any rug pull and can able to let it stay on my wallet then aim to sell it for long term.
It's not even the scam or not-scam argument — even if everything is legitimate(it's obviously not), it's just the simple fact that there are so many more altcoins today that everything is diluted.
Altcoins are risky and taking that risk when the whole market's diluted as you're saying just do not make sense at least for me.
What specifically doesn't make sense in your opinion? Never said that altcoins weren't risky.