The deadline was mostly a problem because the submission system wasn’t intuitive. And yeah, people might end up taking it more as a competition - to be fair, it lasts a good five days as well.
About LD, idk. Afaik it is “the jam” among indies with a more established community, and it involves the community in the voting process. It’s no surprise there are more comments on the pages when the process itself is more involving.
I got great feedback by seeing people play the game on stream.