"Kids like those questions because they feel creative in math class. They're exposed to other students thinking. They get the generation effect with minimal extraneous load. They get to see lots of worked examples..." and so on.
In my experience some kids may like it, but many tune out. If it's welcomed it's because it's a good way to pass the time until class is over. They get to talk, to BS a bit, and "feel creative" but not much math is learned.
It's torture on the kids who actually want to learn something, but for the majority, it certainly is "fun",