There was much discussion about the relative merits of choice and parser based IF after IFComp last year, and it got somewhat… heated! Personally I like to play both types of game, and I’ve written both. I suspect that the audience for choice-based games is much larger, because the parser is a barrier to entry for some players. I’m working on two choice-based games at the moment, and whilst I’d say that writing parser games is more difficult, there’s a lot more to writing choice-based games than some of its detractors realise.
Have a look at last year’s thread: IFcomp 2018 reviews
It raises the same question about separating the voting. Have a read, and you’ll see what a contentious issue it is!
I’ll add my thanks and congratulations to the Spring Thing entrants and organisers!