There are a couple of problems:
- there is no static set of hardware that I use. You can't buy the same hardware even if you wanted to. So, I would have to be testing all the time. Considering that the kernel changes all the time...
- Should I be testing my distro's kernel or the latest mainline? If the latter, why am I testing a kernel I am not going to use for years, if at all?
- where do I even report the bugs? Lkml? Bugzilla? My distro?
In reality, it would be a full time job for a couple of people to deal with all this. Highly paid jobs. Not every business can afford that.
A stable source level API would go a long way towards improving the situation, but that is not likely to happen :-)