When selecting text in Acrobat, it defaults to selecting the entire word, so that editors must routinely deselect text Acrobat has included in error. I understand from past comments that Adobe has no intention of changing this behavior.

But could you at least not consider adjacent punctuation to be part of the word?

If I want to select a word at the end of a sentence, I very rarely want to select the period, too. If I do, I can drag a little further much easier than carefully dragging back just one character to undo Acrobat's mistaken selection.