I really think altcoins are a bubble just like dotcom bubble.
You know dotcom bubble was the caused because people rushed to buy technology companies shares.but the problem was that most of these tech companies did not even have a product or even a plan to have a product.they were just in for the money they can grab.
I believe altcoins are just like that.most of them are just fancy scams looking to get money.
I see what you mean but your comparison is wrong because altcoins are pumped!
the difference is that in dotcom bubble and the similar ones people actually rushed to buy them so the price went up because of that. in altcoin bubbles people did buy them but that was not the reason for this kind of rise. the reason was because of the pumps.
in dotcom bubble pumps are illegal and since the market is regulated you can not do it without consequences but altcoin market is not and it is easy to manipulate it without consequence and also since it is a tiny market you can become a whale with a lot less money.
And when that bubble bursts bitcoin will be shaked but will stand its ground.
I agree with this though. it has been a theory that I have had for a while now. as people dump altcoins they do it on popular altcoin exchanges like Binance, Poloniex,... these places don't have fiat markets (don't confuse tether with fiat) so in order to go back to fiat they have to sell their shitcoins for bitcoin then transfer it to another exchange like Coinbase, Bitstamp, Kraken,... to dump for fiat so bitcoin price comes down as they dump their altcoins and the bubbles burst.