Are people selling alts to buy BTC for the forks?

I see a lot of people happy about the forks because they get “free” coins. It doesnt make much sense for me because the combined value of the 2 chains (say, BTC-Core + BTC-Seg2x) should be the same (or less!) of the original one (although with BitcoinCash it was different).
Anyway, if thats the case, that would explain why almost all altcoins have dropped while BTC went lately. What do you think?

@Avz I think it depends on what kind of trader the person is. I enjoyed a recent video by cryptobud that talked about this (I will attach this video.) My personality is long term so I really don’t care too much about current profits. As long as my crypto portfolio makes a higher percentage return than my 401k over a span of 30 years I am going to be happy. Others trade by the hour and every profit opportunity counts. Hopefully this answer helps you.

What do you think about Ivan’s video about it?

He talked about BTC gold was pre-mine, and they (BTC gold developers) took a snapshot more or less one month ago, that means the only BTCs holded before this snapshot could be claimed.