無茶苦茶ではあるが、そう言いたくなってしまうところが、丸尾君にはある。
It is indeed absurd but/and Maruo has reached the point where he wants to say so.
I can't understand the structure of this sentence. Nor am I sure I've translated it correctly. It's the part in bold that's confusing me (I think). In particular the function of に. To me this reads as "the point where ... is at Maruo" rather than "Maruo is at the point where..."
That に is a place marker (="in/at"). ところ has many abstract meanings, and in this case it can be understood as "trait" or "characteristic". The subject of そう言う is the speaker (="I").
See: Meaning of ところ in アメリカのいいところ
そう言いたくなってしまうところが、丸尾君にはある。
(lit.) In Maruo-kun, there is a trait [because of] which I want to say so.
≒ Maruo is the kind of person who makes me feel like saying such an (absurd) thing.
