Almsost every altcoin is shitcoin and due to it altseason will never happen
why can you give an opinion like that? maybe because you don't have altcoin or you're fooled by lots of shitcoin. Altseason will have a time, the world of cryptocurrency is not only bitcoin but many altcoins don't need to wait for the altseason to rise. So if altseason do not think you will happen, really wrong opinion. In the world of cryptocurrency everything can happen at any time.
I think people say things like that because they have been burned, like you have mentioned, or are just holding BTC and hope all alt money flows into their coin. No different than when folks shill a specific alt they are holding here. That's why I take certain comments by folks not only here, but in more mainstream media, with a grain of salt -- typically whatever they state is to benefit themselves.
Now altcoin season as we used to know it probably won't occur, but that doesn't mean alts will never go up in value. Some people act like BTC is the bestest coin in the world and all alts are complete garbage. Yet of course from a technical standpoint, most alts are much better than BTC. And without alts, and new alts in the pipeline, innovation in the crypto space probably would hit a standstill.
BTC needs alts, if for nothing else, hype and volume. Some may say differently, and we certainly don't need all the alts currently in the market, but all alts vanishing wouldn't exactly be great for the crypto space.