Paul should be glad to have users who are complaining - if he judiciously follows up on them, the complaints will help him Make Something Programmers Want ;-)
Granted, negative feedback reveals targets for improvement.
But!
With all things considered in the current context, it's unlikely that it will achieve any results.
Criticisms make their authors feel good and superior. But they do nothing to make the world better. They probably won't even rearrange the priority list for Arc features, as PG, RM and crew are very busy. Since there is no spare time, criticisms are made useless. PG didn't put out Arc and say "Hey, I'm bored, what should I do next?"
If we-the-users want change, we-the-users need to be prepared to create it. A ten-minute blog post attacking Arc is ten minutes wasted.
So, criticisms do no good. They may do harm, however. Criticisms without contributions will make the Arc authors feel resentful. It's an awful feeling to give something away and have people attack it.
Imagine you gave someone a gift. If they didn't like it, you would expect an awkward pause, a mumbled thank-you, and then the gift would be ignored. How would you react if someone didn't like your gift, and started belittling it and swearing at you?