I'd disagree, especially when you look at the later parts of the skill tree where certain classes turn into tanks and buffers, not to mention how each of the three has 2 sub-classes. You're literally looking at the first five skills which are given to all characters so they can all solo the same content.
Sure you disagree, but every class and every subclass still deals with the same guns, has a super, has something modifying their melee, and has a movement modification.
Titan gameplay: Shoot, throw a grenade, melee, use a super to clear guys out.
Warlock gameplay: Shoot, throw a different grenade, melee but don't actually melee because warlocks are made of paper, use a super to clear guys out. Maybe replace your glide with a teleport.
Hunter gameplay: Shoot from long range, throw a different grenade, melee, charge your gun up with your super (at least this is different). Maybe do a triple jump when you subclass.
From what I understand the subclasses try to specialize the gameplay styles a bit more through incentivizing specific weapns, and change what your super does (like the Sunsinger's super reviving and healing instead of doing damage).
The class gameplay variety is defined by the mechanics unfortunately, and breaking away from the mechanics as is would make it something that might be too different from Bungie's legacy.
I'm pretty confident that when I pick this up, I'll think that my level 20 Striker won't feel that different from my level 20 Gunslinger. Just like how my Phaselock Siren in Borderlands never really felt too different from my Anarchy Mechromancer because I was still shooting guns at people 70% of the time.
