If it happened just once it could've been dismissed as an accident but when you have a level 18 BLU who keeps self-destructing on mobs in a Shadowbringers zone, there really isn't any kind of logical excuse you can make for them doing this.

Even if they didn't use Self-destruct (Which is being done specifically because it has a huge radius and thus doesn't require them to actually target the minion to immediately aggro it), they'd still be one-shot by anything they try to fight.

They've also made it very clear that they don't care about the rewards and are doing this strictly to piss people off because they can/will split up to keep multiple S ranks in different zones/servers covered even if it means missing out on credit.