I personally believe that it's just as hard to make an actually good game on a no-code engine as say, unity or godot. If you don't feel challenged by using a no-code engine, then mabey you should consider switching. All that to say, I think it's fair. (Take note: I am not the jam admin. They might have a different opinion)
While knowing how to code does provide an advantage to solo developers in the form of custom scripts which provide flexibility, doing so requires time and effort just like any other discipline, and in my opinion doesn't provide anything more valuable to a game than any other custom made asset, be it art, sound, game design or balance.
As you mentioned there are options out there for people that don't know how to code, just as there are options for someone like me who doesn't know how to make art. It's all about give and take, finding your strengths and passions and putting whatever they may be into the game that you produce, while doing your best to cover for whatever parts you're less skilled at.
I'm also not a jam admin, just a programmer who's passionate about their work.