I've never seen an interesting point that could be made in 140 characters or less. That limit works for jokes, headlines, and almost nothing else.
Single-tweet "wisdom" always turns out to be something so broad/unqualified that it's uninteresting or untrue. VC Twitter is basically a deluge of that kind of faux-profound nonsense.
At first I found it surprising to start finding all of these Twitter threads making it to the front of HN and thought "well, it must be a really compelling message..." Now I just ignore them altogether. It is a very distracting medium for the longer posts, and that distraction shows through from the writers side as well.