Here's a bit of math for you.
White weapon does 157 damage and has 10% recoil reduction right?
Well, then there's this seemingly worse blue weapon, with only 121 damage right? But those modifiers are a dandy 2.4 zoom, +150% critical damage bonus and +50% damage bonus with 20% rate of fire bonus.
Do the calculations. Now imagine that sexy 50% damage bonus being hidden because less important stuff like zoom is filling up that slot. Now imagine you sold that weapon because you thought it sucked.
Now, proceed to rage.
I believe that the damage bonus is already added to the damage modifier of the weapon already, so it should still show 50% more damage than a default weapon of that type.
Anyway, I don't find all that many weapons with 5(+) modifiers, it's mostly just orange weapons with elemental damage, since that takes up 3 lines (elemental description and red flavor text), so you haven't missed all that much, really. And on those items that misses a line, it's usually the scope, so you can easily see if it's there anyway.