Why not tablets for vertical markets?

The first flurry of tablets came out in the early nineties. The technology wasn't yet good enough to be attractive to consumers, so the talk was about vertical business markets. Insurance claim adjusters, aircraft technicians referring to manuals and diagrams, hospital staff doing the rounds, retailers taking inventory etc., basically everyone who works on their feet instead of sitting at a desk and needs some form of data processing should find tablets handier than laptops.

And the vertical markets never happened. As soon as everyone realized the technology wasn't yet good enough to be attractive to consumers, the entire nascent tablet industry just went into the recycle bin.

Tablets came back in a big way when the technology did get good enough to be attractive to consumers. Vertical markets should ride on the back of that, right?

But it doesn't seem to be happening. All the news is about stores clogged with hundreds of thousands of ADD-inducing entertainment "apps"; the use of tablets for domain specific business software is never mentioned, and it's hard to see how it would even be possible if everything has to go through the "app store".

So - why not? The logic still seems sound; tablets should be ideal for vertical markets; why isn't it happening? Or is it happening and we just don't hear about it?