(I see there are a lot of similar questions, but answers are not really what I am interested at.)
The thing that is bugging me is indirection. If I'm writing something, I do tend to inline as much stuff as possible. I might be less strict about it in compiled language hoping that compiler will do all the inlining for me. Still adding layers of indirection feels to me like "I'll just add some more burden onto user in runtime so that I could have nicer code here" - something that could be solved with either a comment or a different design (which I would actually prefer but it would take some more time). Seeing a small function that is used only once I have to actually fight the urge to inline it. Having a multitude of single-use classes makes me want to create a different (and usually totally procedure-oriented) solution.
How bad is that? How many layers of indirection are actually OK to have?