That seems overly harsh. I'm not particularly high on him but he's been nearly universally regarded as one of the top prospects of his age group. If anything the talent is there but he needs a mental adjustment to win, which is exactly what a lot of coaches at that level help with.Felix lacks the necessary talent to be with Toni. Will win 0 Slams with or without Toni.
Who would you say "deserves" to be with Toni anyway? A man who doesn't exactly have the most diverse coaching resume. Toni might just be a really average coach for all we know and happened to get to work with one of the most talented players ever.