Yes?

> Pedophilia is termed pedophilic disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and the manual defines it as a paraphilia involving intense and recurrent sexual urges towards and fantasies about prepubescent children that have either been acted upon or which cause the person with the attraction distress or interpersonal difficulty.[4] The International Classification of Diseases (ICD-11) defines it as a "sustained, focused, and intense pattern of sexual arousal—as manifested by persistent sexual thoughts, fantasies, urges, or behaviours—involving pre-pubertal children."[6]

* https://en.wikipedia.org/wiki/Pedophilia

> Pedophilic disorder is characterized by recurring, intense sexually arousing fantasies, urges, or behavior involving children (usually 13 years old or younger).

* https://www.merckmanuals.com/home/mental-health-disorders/pa...

Sure, if it causes intense distress or interpersonal difficulty then just about anything is a mental illness. For every person like that I'm sure there are many for whom it's just a fantasy that excites them to think about but they'd never actually act upon and isn't really a big deal. There are a lot of fantasies (not necessarily sexual ones) similarly enjoyed by mentally healthy people every day.

It is pretty culturally determined what constitutes mental illness. The underlying cause might not be more different to foot fetish, maybe even treatment is similar.

One is just morally not questionable.