Let's number the sins:
1. Introducing itself as an e-sports game (Metroid Prime Blast Ball) during a MAJOR event (Nintendo World Championship)
2. Considering AM2R, a fangame, a threat and trying HARD to erase it.
3. You only have TWO CHOICES of aiming: Gyro Aim and Game Cube-style Aim. Both of which requires you to lock in place.
4. Glitches. You can get stuck in a death loop if you enter the lava, while a cutscene plays, for example.
5. You don't play as Samus AT ALL. Samus is even an ENEMY at a point.
How they could fix:
1. Introduce it as a deathmatch game (reminding people of Prime Hunters)
2. Give recognition and praise for fan effort (something Capcom and SEGA did. Heck, even KONAMI and NAMCO did at least once!)
3. Kid Icarus Uprising and Prime Hunters had two additional aim choices: Button-based and Touch-based. They could have added those in.
4. They didn't bother testing it long enough, OF COURSE. Could have tested it for longer.
5. Single Player campaign could have been around Samus.