While its true purim is a time to have fun, this isn’t mutually exclusive with learning. One can learn at night, and have a lebedike time during the day.

And I find it very hard to imagine bochrim voluntarily learning could cause “a backlash, and we’ll wind up losing purim altogether!”

rav shach once said about bain hazmanim “if you take away bain hazmanim, there will be no zman”
purim is, and always has been, a time for levity and fun, even in the times of gedolei olam long gone like the rambam, rashi, the rema, the yaavitz etc…all of these people had a lebedike time on purim, and once you apply the chumra culture to purim, the results will inevitably be terrible. there will be a backlash, and we’ll wind up losing purim altogether!