If you hold Godzilla to the character's persona in films like Gojira, '84 and Shin, then Minya is one of the biggest WTF inclusions in the entire franchise.
If you view Godzilla more like a comic book character who has numerous variations over their decades of existence, Minya fits within the realm of the kid-friendly Showa films, unfortunately, he was also the downfall from which a few solid recoveries came but overall fizzled out by '75.
For me, I embrace Minya because I was like 5 when I started watching these movies and I loved the idea of a little Godzilla that was like me and having Godzilla for a buddy or a dad.
Had I been exposed to the movie in my adult years, I may look at him like, what is this ****? Along those lines, I don't really like Baby Godzilla or Junior from the Heisei films. That era, overall, has a pretty serious tone, and when they took another aspect from the Showa era to do over again, it just doesn't work. Nor does his seemingly forced inclusion in Final Wars.