The biggest issue with Smackdown's comedy is a WWE problem and not a Smackdown specific problem. *Most* of these writers are still stuck in the attitude era trying to do Southpark and Jackass style comedy when nobody is checking for that anymore. That was edgy and on trend in 1999, but it's corny and played out in 2018. Add to that they're trying to be Dane Cook frat boy funny in 2018 but also keep it PG. The result is a lot of cringe and struggle segments.
The comedic stuff that works *usually* is a result of the talent organically getting it over because of chemistry (Truth TV, Fashion Files), understanding what's culturally relevant/trendy and how to relate it to the audience (New Day) or people who understand how the entertainment part of sports entertainment works and actually being funny and entertaining (Miz, Rusev, Elias). We get a fair amount of comedy in the WWE...most of it is dated, corny, and cringe. That's a craft issue and reflects poorly on creative.
Less comedy isn't necessarily a bad idea in theory if they execute it by paying attention to what works with today's audience and when there's comedy emulating that rather than trying to serve is PG American Pie in 2018.