> Kunreisiki is also better for serious Japanese learners as it greatly simplifies the description of Japanese grammar: cf. matu/matte/matimasu (all with the same verb stem mat-) vs. Hepburn matsu/matte/machimasu (with 3 different verb stems)." This is a silly argument because anyone learning Japanese is going to need to learn how to pronounce it anyway. Also "serious Japanese learners" would likely be using kana.
I think the exception is people using the JSL textbooks :) there is a reasonable defense to using JSL. But you’re right. I think it’s indefensible to teach Hepburn to people interested in learning Japanese.