It is not just the people you named who are basically saying altcoins are useless. We all know it and we all have been saying that
altcoins are useless. They have no future and the "Greater-Fool theory" is describing the situation in altcoin market very well.
But none of it has anything to do with bitcoin and what it is or isn't going to do in the future.
How long will this market correction will continue and where will this stop.. and where will Bitcoin stabalize
It depends on what market you are talking about.
Since you use the term "crypto" then I have to say what is happening in the altcoin market is not a correction it is a dump and it didn't start recently to stop, it started in 2018 and has been ongoing.
What we have in bitcoin is also not a correction, it is a crash and since it is not a logical market behavior it is not possible to predict when it will stop.
I belive BTC is coming back very soon. Be patient guys