I am a user in several SE sites and I regularly observe the following situation. There are posts with many good answers and the OP stalls to accept any of them. First of all I am aware that:

 1. When I say ``good answers'' that is based on my personal opinion and that the OP may have a different one. However, there are lots of cases where the answers are very informative, to-the-point and address the OP's question in all extend. This is not subjective.
 2. I also understand that the OP does not have any responsibility to check on their post 24/7. However, this argument also breaks down in lots of cases, where the OP stalls on accepting a good answer but discusses extensively in the comments section (possibly asking more sub-questions instead of clarifications on the original question).

This brings me to my question(s): Is this behavior a good etiquette? Does it violate any SE rules?