and i think the same principle would apply on altcoins as well
i mean if u truly trust in the project and u see potential in it in long run
then i don't see why u couldn't hold on to altcoins as well
Altcoins are more or less short term projects and many of them are pump and dump coins, that is why it is advisable not to hold them for the long run, so you don wake up as a bagholder someday.
That said, the reason we hodl bitcoin for the long term is because it has an actual utility, its use cases and global adoption is there for everyone to see; you can't say the same for most altcoins, many times they are created solely to enrich their creators, so that's why it is not advisable to hodl them for too long, and so many people learnt this from experience.