I’d like an explainer. I’m not a basketball scout but have been watching college basketball for 40 years. My eye is pretty well calibrated as to who will make it to next level (except for Tyler ennis).
I'm happy to break down the thought process of some of the NBA folks on QG. I'll put a tl;dr at the bottom.
Biggest thing for scouts with QG right now is he has all the things you can't teach: Size, athleticism, NBA frame/body. The things he's struggling at are all teachable -- the shooting form is strong, so that tells us he just needs minor tweaks to footwork and more reps.
The shooting stats are certainly iffy, but scouts know he's playing in a guard-dominant offense that doesn't run any plays for him. A key thing scouts will want to see him improve at is the free throw shooting -- this tells us whether or not he has a balanced, mechanically-sound shooting motion or if he needs a rebuild. Studies have shown FT shooting in college has a strong correlation to 3-point shooting in the NBA.
Defensively, steals and blocks have a strong correlation to being an outstanding defender as they show the ability to anticipate the play. He's at 0.8 blocks per game from a forward spot, which is fantastic, and the 0.5 steals is solid, too. The athleticism/body tells scouts he'll be a good on-ball defender at the next level, and they'll find out at the combine almost instantly if the zone hurt him in any way when he plays 5v5. I expect it won't and it's just a talking point for analysts to fill time.
He likely projects as a 3-and-D type player in the NBA, which is super, super desirable right now. Biggest knock is probably the foul trouble. That shows us he's undisciplined and takes into question his decision-making skills. Again, those are likely fixable (unless you're Dolezaj and Sidibe, who are both on Year 3 of their ACC Hackathon).
He's certainly a ways off and I think his stock in general is lower than it was coming into Syracuse, though I think a lot of that is his role in the offense isn't what scouts hoped it would be. In limited opportunities on offense, he's shown an ability to slash to the rim as well as battle against bigger players for rebounds, which tells us he great body control.
While he may technically be "small" for a SF, that's mostly referring to some of the stars that have fantastic size. I think I saw a PJ Tucker comp in here that I like, though I think QG has a higher ceiling based on the athleticism. I know PJ Tucker isn't a super sexy name fans may want to foam at the mouth over, but that will get the bag from literally any NBA team, and that's what's important here. I know fans would like former SU players to be stars, but it's important to remember that there's only like 15-20 actual stars in that league. It's OK to be a role player and, to be quite honest, that's what the majority of the draft is shooting for.
TL;DR
He's good at the things you can't teach (size, body, athleticism). Has strong framework for his shooting mechanics which says he just needs minor adjustments or more reps. Steals/blocks tell us he likely defends at a high level in the NBA because of an ability to read the play. Biggest knock is the foul trouble -- calls into question his decision making. Scouts will consider his role in the offense (trying to rebound Buddy's bricks). In limited action has shown an ability to slash, run in transition, which is a priority at the next level.