3Lo3Ts are prone for underrotation calls. Not sure why not the 3S3T but he probably thinks the 3T3T is sturdier, likelier to look visually bigger and guarantees him better GOE.
Some people are just not natural jumpers (or natural lutzers/flippers) so sticking with the jumps you're confident will land and will look best and ditching the ones that will get you negative GOE is a good math strategy

it's not like he's a slouch in the tech department... his 4T and 3A are pretty solid, 4S and 4Lo waiting in the wings while he paces himself for senior.