He's got bad control issues and has his whole HS and college career. Once he gets to A ball he's gonna face a different animal hitter-wise. Those guys hardly ever swing at bad pitches even at that level, and the umpires are waaaaaay. better. You aren't going to get those borderline strikes like you do from NCAA flunkies making $250 a game. Brecht's BB/9 was 5.6 which was down from last year but still way, way too high. Hit 12 batters and threw 10 wild pitches as well. His ERA shows it.
I know people like to bring up his velo, but even at A ball those hitters are seeing 100 mph every day. Guys throwing that hard are a dime a dozen and have the disadvantage that almost all of them end up with Tommy John and give up a year and a half. TJ surgery is so common it's pretty much a given now. 100 mph is not a magic number and hitters are just crazy good nowadays in the minors/majors.
To top it off, there is AA, AAA, and the show after you get through A ball, and at each level the hitters get exponentially better, not just linearly. He's got a long hill to climb and scouts know that which is likely why he dropped so far. 2nd round ain't terrible though.