For mathematical or in general scientific facts, I can build clear frameworks and descriptive languages, in which I can express my thoughts clearly. If I read someone else's, I can usually understand parts and even use them without understanding the whole thing (i.e. I can use a formula without being able to derive it).

In philosophy, any thought can be understood in a multitude of ways, especially depending on the way I come up with the thought. This means I can explain something as well as I want, the other person maybe can't ever understand it without walking the same path I took. Or the person can misunderstand me, without either of us ever noticing.

But, as much as formalization might help with these aspects, it would also lose much of the romantic and experiential aspects of philosophy, which would fundamentally change it.