Starting out on the road not the gym

[VeloVT]

Actually, I said "If you ask me 120 is still too thin for someone your height to be"
which clearly identifies it as my opinion, not as a "categorical statement".

But other than that I agree with everything you said!

Well, the statement is categorical (regardless of whether or not you explicitly identify the view as your own) because you've applied the characterizations "too thin" and "having no muscle" to an entire category of persons (those 5'5"ish and 120 lbs), without admitting the possibility of exception. There are a lot of folks generally in that category and some of them (me) might object to being thus characterized. (Plus if you saw me, you wouldn't be tempted to call me those things).

However, I'm in complete agreement with the general view that it's much more important to be healthy and strong than it is to be thin.