There is nothing about boycotting the altcoins but people prefer to invest safely in Bitcoin which is relatively trusted in the crypto space. Also there are too many scams in altcoins so people are largely afraid if they may be caught in of those .
Altcoins this is tools for more experienced people, because they know how to choose the right coins that have stable development. Scam projects getting money from greedy people who do not want to study anything
Since altcoins now have more than seven thousand and their number continues to increase, a significant part of them does not inspire confidence among investors. Overall, however, altcoins continue to evolve rapidly. There are still a lot of useless altcoins, but they continue to be eliminated, only those who perform useful functions and are in demand remain. Therefore, altcoins are not boycotted by investors; among such a multitude of them, about ten percent are worthy for investment.
Perhaps I will give an incorrect comparison. I apologize in advance. To me, altcoins mostly resemble used toilet paper. Because they primarily serve only one rise in prices and then no one needs them. And some are not even able to do this. There are altcoins that are really valuable for the crypto market and have great prospects, but there are very few of them and you can count only a few dozen.