Inherently consulting struggles because of two things:
1) Consultants usually consult clients on issues where the clients have little knowledge. So it's hard for the clients to challenge consultants on anything.
2) Consultants usually work by the hour which does not align incentives with clients very well. They have little incentive to work quickly and effectively because the slower they are the more they can charge you. This can backfire if the consultancy gets a bad reputation which is why you see reputation being very important in consulting.
Designing better incentive structures is really difficult though.
I would say yes the world of consulting is full of bullshit, especially in America (from what I hear). Scandinavia (from personal experience) is better but not great.
Contrary to other sectors/business, in consulting the first group is harder to find.
In my personal experience and view point, yes, it is full of it. And it's part of a bigger ecosystem full of it.
Insider from the consulting business: no
Opinion: Yes it's full of shit