Why is のに used in this sentence despite the lack of contradictions?


> ちょ。。ルーク！ まさか、 その柱を登るつもりー

> あー痛かろう。。。

> 足場もないのに

> さすがによじ登れんよ

This sentence is all spoken by a single person. He thinks a character will try
to climb a pole to catch an animal.

Why is のに being used? Wouldn't ので make more sense? "Despite the fact there are
no places to put your feet on, as expected you can't climb it"




のに would indeed sound weird if this was a statement that conveys the fact that
one can't climb the pole **because** there're no places to put their feet on.
However, we can tell from the final よ (or the context or the tone with which
the sentence is said even without it) that the purpose of this sentence is not
that. It's said as a caution or reminder to someone who is thinking of
climbing it **despite** the fact that there're no places to put their feet on.
This makes のに natural. If you're a speaker of a less context-dependent
language and feel something is missing, you could read it as something like
足場もないのに（登ろうとしてるけど）さすがによじ登れんよ.

While ので is OK, it seems to me a little weird in this context because the
other person is there and shouldn't need an explanation about the lack of 足場.

