I'm not sure if this is still the case, but one of the earlier shows was a reconstruction of a basement bathroom owned by a cousin of my wife. According to her, the owner had to pay one half of the cost of the reconstruction. I doubt that this is the case in all instances though, especially where the owners are destitute.
The Schluter Ditra you're referring too can be expensive (~$1.25 to $2 a sqft depending on bulk qty an source) depending on your point of view. However, compared to having to rip a tile job up due to cracking grout/tile and repair or replace - its cheap insurance. With modern (post 1970s) north american construction methods, many structures are not nearly as rigid as they used to be so these types of membranes are especially needed on the typical joist & plywood floors to prevent cracking grout and/or popping tiles. I've even found it beneficial on concrete floors as a thermal break (keeps your toes a few degrees warmer).
I've used Schluter products several times and have always thought they were worth the money invested.
Now regarding his show, I do enjoy it. My take is he goes over the top to prove a point and provide a demo for the TV audience. It wouldn't be that interesting of a show of he was called in to fix a slow draining bath tub and all he did was run a drain snake! As with everything on TV these days, there has to be a little showmanship and a little drama to cater to the mass audience. I'm definately not a fan of the drama but I would be lying if I said I haven't learned a few new tricks or design ideas from his show.
If his goal is to increase minimum code as a previous poster mentioned, then I do have to give him a few more props as I too believe the minimum code isn't satisfactory. For example my local county still allows greenboard drywall in wet areas. I can tell you from experience that tile and grout is not an effective water/moisture barrier and you WILL have mold, tile pops and grout cracks with in a few years if not a few months. Do it right, do it once.
To the argument that many of his techniques would drive the basic house up to McMansion prices, I think that would be true if you went over the top on finish materials as he does (granite counters, exotic wood floors, etc). However, I think a lot of the minimum code upgrades he seems to be pushing would probably save a homeowner in the long run due to decreased utility/maintenance costs and less likely hood of having to repair/replace failed systems.