They’re rolling need on loot they don’t need or can’t even use because they intend to sell it to strangers. Back when LFR was new and group loot was standard, Blizzard decided rolling need on items to gear up your friends was something they didn’t want to happen and created personal loot. I bet those players take paypal.
They think the best geared players deserve to get money from badly geared players, that Blizzard wants this to happen, and has designed the system to facilitate it. They think if those players deserved the gear, they would have it already.
The fact is that we hear complaints a lot that people are permitted to roll on items their class can’t equip, win multiple need rolls on identical items even though others have also rolled need, or win every item off a boss. I’d be curious how the supposed restrictions were implemented, because it seems they were not.
But I’m certainly not going to enter raids to find out. I’d never raid as long as loot distribution is controlled by those with no moral compass.
In fact, they probably treat others in their guild the exact same way. Not useful to them? Pay up, sucker.