Because there are other really good players out there who are also performing extremely well, and/or have better projectability?
I really, really like Catton, but Demidov looks terrific, Silayev is playing a regular shift and doing well in the KHL, Levshunov has great tools and is performing really well in a better league, Buium is also having a great season in the NCAA, Parekh is having a monster season, etc, etc.
The doubts on Catton are because of his size and strength, or lack thereof.
Silayev isn't producing offensively much right now, but looks like a quality defense first D on a top pair or at least top 4.
Levshunov impresses me in that his game is balanced, poised, good in all areas of the ice, but doesn't have a dynamic offensive element.
Buium is dynamic as hell, I like him. High ceiling type.
Similar with Parekh, but interested to see how he defends once he gets to pro, I know Saginaw runs a different style of system with their D that is offense heavy.
Demidov is awesome, shifty, creative, interested to see how he adapts to the North American ice.
Catton is so creative, high hockey IQ, reads the play well, finds teammates well, finishes off scoring chances. Clayton Keller type, but with more projectable bite/edge in his game IMHO. I'd take Catton in the top 5.