It is also the consensus position for a lot of bad reasons though.
There is an assumption that belief in, or even reasonable agnosticism towards, any other theory can only be motivated by racism.
There are many people that believe OOA because they want to believe it, because they want to believe we are all more similar than we are different, etc.
Multiregional hypotheses are perfectly plausible. We have very limited information one way or another. Out of Africa may be more likely but it is far from certain.
Function length also depends on language. Every line of one language requires three line in another if the former has implicit error handling and the latter explicit. But I find the cognitive load of the two to be similar.
I am also okay with 1000 line functions where appropriate. Making me jump around the code instead of reading one line at a time, in a straight line? No thanks!