For me just opinions
Under 2300 grimoire
Hezens vengance users
Fusion rifles
My team in crucible because they always get only 1000 points in a match
Blue guns
People without atleast 10 exotics
Havent done hard crota
Cant run sword
Cant run relic
Suck it noobs
Git gud scrub
Scrubs
3 of same class
Grab heavy ammo without waiting in pvp
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The list goes on and on. But mainly they are a noob if they got the game on Christmas or later.