That's not what the article you cite is saying. It's saying "don't use Signal because Signal is less than perfect". Calling the counterarguments in that thread "protectionism" suggests you feel likewise.

If you want to discuss how a follow-on from Signal could and maybe should address some or all of those points, great! That's a conversation worth having. But it doesn't sound from your toplevel comment as though it is the conversation you're trying to start.