"Do you know how much effort has to go into learning to play an instrument? On the other hand everyone can sing."

Ok, can we please finish these incomplete sentence?

Do you know how much effort has to go into learning to play an instrument well enough to go solo?
Yes I do, and it is very considerable.

On the other hand everyone can sing...well enough to join in a chorus. On the other hand it takes an incredible amount of effort to learn to sing well enough to hold an audience solo.

We need to compare like with like. I am a barely competent musician. On the rare occasions I want to play a solo instumental I agonise for weeks and practise for months. But I can join in a session without virtually any preparation at all.

And therein lies much of the problem - the barely competent musicians who hunt in a pack, assume to their own playing the level of competency actually coming from the virtuosi who are leading the way, and on that basis feel strong enough to tear the throats out of any singers who cross their path.