Not many, only some.
And the media is only reporting what gets them the more attention. At times like this when price has not made any major moves for more than 2 months the negative articles will get the most amount of attention so obviously they keep quoting those who have said something negative about bitcoin. In a couple of months ago when price was rising consistently every week the exact opposite was true as they published anything that was positive.
Why are these people positive or negative about bitcoin? In my experience it is almost always out of self interest.
I would say the OP is right and the majority of economists calls Bitcoin out as being a big fat bubble but nothing else. Maybe they lack understanding, maybe they are even right. First and foremost I think that a lack of knowledge in technology combined with monetary theory may lead them to their negative conclusions about Bitcoin. Most of them often argue that it is inconvenient and expensive to use, but that is only the first half of the sentence because Bitcoin can improve. If you just look at that statement, they are correct. For now Bitcoin isn't what it probably is supposed to be, but that doesn't mean it is the end of the story as those economists often put it.