Speaking technically, the title of this thread, "watching paint dry," is a noun phrase based on a gerund.

What would count as a "sensible" comment to a noun?

It seems to me that a thread with a nounal title would be essentialy an exercise in word association.

Now, word assocations are neither sensible nor non-sensible. They simply are. In some contexts, They might be viewed as symptoms, but then again symptoms are neither sensible nor not sensible.

On Mudcat there is all too often a tendency to miss the essential point of a thread, but I do not think that this is the issue here.
What we have here is, if I remember correctly, a garden variety "category" mistake.

Hope this helps.

Russ (eternal guest, part-time pedant)