Whenever there is a rumour or news of a bitcoin fork it stops the progress of the Alts making Alts lifeless or killing them. It seems bitcoin forks support bitcoin market dominance over alts.
The question is will there be more bitcoin forks after segwit2x fork? Because if there is then thats gonna stop Alts in its tracks.
No.
Bitcoin forking is mostly realted to hype.
Altcoins should be related to its function,
to its specification.
Altcoins may be very very very good,
I even believe that one of the Altcoins may replace Bitcoin someday.
Forking is not killing Alts, it is related, it doesnt kill the other.