A Kineticist can only have one element gathered at a time, leaving the other hand free with nothing special to use it for, and Elemental Weapon is restricted to one-handed weapons only (we'll see if the two-hand trait being usable remains for the final release).
Only a few abilities mention using both hands (Tidal Hands, Hurtling Rockfall, Ferocious Cyclone and Fusion Blast) and half of them are only for flavor. That leaves me with the question: Why?
I feel like Kineticist should have more abilities that allow for the usage of both hands to either increase power (when doubling down on one element) or versatility (when wielding a different element in each hand).
Let me channel lightning with both hands. Let me smash people with a rock maul. Let me go full Todoroki and use ice and fire simultaneously.
As is, the heavy lean to one-handed usage feels like a pointless nerf with no thematic reason behind it.