How long of an answer do you want?
Trikes are different than bikes because they don't lean in the corners. That puts side loads on the wheels that bicycle wheels don't have to contend with. Taller rims are going to have to contend with more side load stress than smaller ones, but I assume there are design adaptations to solve that.
That Atomic Zombie wheel assembly, by the way, is home made (including the hub) and relatively crude compared to a factory produced trike. I wouldn't use that example for a very significant part of my decision making process.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.