To Reaper and Westford, this is a matter of what a map is made for, in this matter Asylum is CQC.
Though you may be able to play long/mid ranged weapons successfully in Asylum that is besides the point,
as a player on Asylum you have to push a lot of chokes, that can be extremely hard for a player to push if you have a spammable AOE(Area of Effect) damaging weapon making that push impossible.
Though it may also be hard to push a JG on a corner you can flush out that spot with a grenade or two.
Having someone just clicking M1 with almost no need to aim is frustrating and out right boring(+teamkilling can be and is an issue).
The game is not supposed to be egocentrical it is supposed to be fun for everyone, it is not fun to be held down on a choke, it is not fun to be incapable of pusing because someone is pressing
M1 from time to time being rewarded for a low effort playstyle.
It is not a formidable defense, it is a cowards response to low effort and high reward gameplay.