Due to their length people are less inclined to read them and answer them.
I don't entirely agree with you there; whilst some long answers can be a deterrent from reading, if it's on a topic that I'm interested in or have the ability to answer, I'll read it; sometimes these are the better questions, in fact, since:
- They can be more detailed than shorter questions, and less ambiguous and actually make sense compared to some very short, or shorter questions.
- Often the longer questions are more specific than other questions that are popular and everyone goes in to answer, so I'm more likely to get a good answer in than in a popular question that lots of people know the answer to.
- They can often be more thought-out than shorter questions where the user has asked a simple question without doing a search beforehand, so can be more interesting.
Therefore I don't think it's necessary to tag questions as either long or short, because long and short questions can both be good or bad.