Pretty much anybody who's anybody in the Melee community has some pretty strong opinions on the game. Some views aren't seen as outrageous by the community because they generally align with public perception, but there are some opinions that don't go over well.
Though people respect him for what he's done, sometimes the opinions of Aziz "Hax" Al-Yami seem a bit off. For example, Captain Falcon being a low tier is a meme that he's solely responsible for.
For the most part, this tier list isn't strictly bad. His views of the top three reflect what some top players have been saying, with Jigglypuff's placement making perfect sense given the results of Juan "Hungrybox" DeBiedma. The bottom part is the odd section.
The arguments between Peach, ICs, Sheik, and Falcon are pretty subjective ones, but most people agree that ICs are the worst in the list. Still, it's his opinion that he's entitled to, and the inclusion of these specific characters on the list means he thinks they're at least semi-viable.
Just for comparison, this is what he thought the last time he released a tier list. The implication this person was making is that ICs are as high as they are because Kyle "Dizzkidboogie" Athayde gave Hax trouble in Losers Finals of the most recent Apollo, so he's making up for it by ranking them higher.
Realistically, it's probably just what Hax thinks. Regardless of other people's thoughts, he's entitled to these opinions, just as much as William "Leffen" Hjelte is allowed to think Marth beats Fox. Especially since we're not top players.