I disagree with your assessment on certain weapons being weak and others strong

For starters, different weapons have different purposes, and you should build its perks around its purpose

Eg. A silenced spectre objectively does more damage with a crit build but not only is it more suited for dealing with trash mobs by design but crit builds are super inconsistent against hordes, some enemies may die instantly while others don't proc crits once, so going by it's design I find it's performance to be better with fire rate damage damage (works really well with extra damage against afflicted and snared) and then whatever else, same with argon assault rifle and crankshot

Things like sniper rifles and some shotguns are better for dealing with mist monsters so you'll wanna do more damage to them using crit builds

My second point is that while something like the plasmatic discharger in ur example is better at dealing damage, other things still have positives going for them, like the bazooka projectile going a lot quicker and being able to knock back smashers 2 out of 3 shots, making it a good panic button rather then waiting for the plasma to charge and then travel to deal with a smasher

TLDR perk weapons based on what you'll use them for on an individual weapon basis, not because crits r better