Glacius is not bad, and he has tons of setups, however, hes not on par with the top 3 and is lacking tools to win tournaments consistently. Here is what I believe are glacius' problems.
He lacks mobility (no dashing) and in a game thats super aggressive and promotes disrespect. thats already a major weakness. The purpose of glacius is to control space and make you inch your way in. Funny how at the start of the match before it even begins you can walk up to him.
He has range on his normals and air normals but they all have terrible priority and are easily stuffed. His lance has range but it has massive recovery and is super negative on block, also has terrible priority (try to meaty someone with a shoryuken on wakeup with it and watch what happens) and characters that can lower their hitbox substantially can negate the lance, Sabrewulf comes to mind. His ground shatters are telegraphed and can be jumped, dashed, or shadow punished on reaction. His hail is the best aspect about him because it sort of acts like an assist, but is not all that great. When he summons a hail you get a free pass to dash in due to the recovery frames, especially as sabrewulf, or if you're Jago and have meter you get a free shadow windkicks.
He can yoga snipe you if you get wreckless jumping, but in all honesty thats no big deal in this game. In SF you have to respect dhalsim's stretchy limbs and snipes because they do damage and will kill you if you get wreckless. In this game damage comes from combos. A few yoga snipes wont deter someone from jumping. I understand his design and concept having messed around with dhalsim myself, but in this game it just doesn't cut it.
He's also a large character and is susceptible to crossups. Free on wakeup and easily bullied. No real mixup potential. All he has are gimmicky setups that worked months ago but players are leveling up fast. At this point in the game the setups glacius has are unviable and easily negated. Only good setup he has is the combo breaker setup which is not unbreakable, it can actually be blocked and/or countered, but it gives you a nice little mindgame and can condition opponents. I give props to filthierich, he pioneered most of the awesome tech and still continues to use glacius and is probably the best glacius out there right now. Glacius is a good scrub killer or good against people that aren't experienced with the character since most of his offense revolves around setups and gimmicks. Once people know the setups and learn the matchup and learn how to counter his setups, it goes downhill fast.
Im not saying you can't win a tournament with him, it is possible, but the odds will be against you by a large margin and you will have to play completely on point and make godlike reads. With glacius facing high level competition, you don't have much room for mistakes like you do with other characters.