With a few replies along these lines here, it seems to be worthy of a separate entry

People buy bitcoins but then they have to sell them for altcoins (according to this reasoning). All in all, it means that Bitcoin sells and buys necessarily balance out in the end, with the net effect on Bitcoin price being close to zero (technically, it is not quite correct but it pretty fast approximates to that state in the long run). And that's not all, obviously, since it is what comes next that matters most here, and so many people forget to think about it

These pump and dump schemes steal money from wannabe investors, and that is the end result which ultimately counts. So if some or even most of these 5,067 altcoins are not technically dead (read, delisted from all important exchanges), this doesn't mean they are not left for dead with the orderbooks empty on the buy side (read, there are no more idiots left willing to buy these shitcoins)