Co-op hostility between Low/High rank

Something that's just baffled my mind is how some players who might be new or aren't that far into the game feel that high ranking players who have better armor/weapons ruin the low rank quest when they join. But on the other hand, there are high rank players who get pissed off when their teammates don't have as strong a build as they do?

Are there not literally lobby settings for these things?