I don’t find PUGs bad, or at least I didn’t. I don’t have friends who play BL3 so all my efforts at MP are just random joes. You get a range of skills but folks usually cooperated within the reason needed for the game and helped downed folks.
I haven’t seen modded weapons, at least that I know of but I’m on console where they have, in my impression, been slower to infiltrate. What has killed MP is M2. I haven’t had a decent MP session since then as groups are long, long time to find (fewer players?) and grossly unstable as people just drop out.