We can't just simply say to others not to complain.
Yep, why people musn't stop complain? They have the right to complain, we have a freedom. I hate if someone limits the freedom, moreover if the situation is getting worse and it is normal to complain the situation. Unless doing a stupid thing, we must understand if people complain. Now we have many difficulties, the economy is in crisis, many people lose their jobs.
Anyway, although we know this will end someday, but when it is? No one can answer it, or ensure us about the possible day for the end.
Nothing wrong with complaining, the issue is that complaining alone does not solve your problems, if after seeing the problems you have had because of the economy and the pandemic you do something about it then I could even say that complaining in that case is the right course of action as it improves your life, but in my experience most people that complain about something do not do anything to solve their situation and that is when complaining becomes an unhealthy attitude.