I doubt that loud angry BB player was any better with Thorn considering that he/she thinks Thorn is a sniper xD
To answer your question, Thorn’s damage per shot is huge so any hit counts and every hit hurts. She has a high crit multiplier but Thorn’s true power lies in her abilities, if you can’t hit crits often take the level 1 L augment and slow enemies in your Blight, a slowed enemy makes for an easier shot. Volley fires five high-velocity arrows, chances are you’ll land crits without meaning to . Thorn’s damage potential is huge, but she’s not a true sniper and crits though effective aren’t necessary to play well with Thorn. Practice critting larger slow moving targets, like ISIC who has a huge crit in the middle of his body, or Montana whose head is tiny but he’s about as slow as a shark swimming through sand. For the smaller and faster characters, if you can’t land a crit don’t aim for it, just tag body shots until you’re confident enough to aim for crits on moving targets.