The number of people doing this is higher than is represented in those numbers because I think many people just stop reporting it because nothing ever seemed to happen. I'm dissapointed with the attitude of some of the community who seem to be making excuses for this. I'm more dissapointed and frustrated with Frontier on this issue.
The fact that there is a 15 second log out timer is pathetic - it really should be much higher, although I'd question if it should be possible at all. Leaving combat 'gracefully' or by pulling the plug is really the same thing and it undermines the very integrity of Open play, wastes players time, and ruins folks genuine game experience in Open. It amounts to an exploit and is cheating.
The fact that Frontier have set a 'graceful' log out so low (15 seconds) doesn't help tackle the issue but it would seem they are not interested in addressing the issue either way. I don't think I've ever witness a company take this approach before. Its highly unprofressional and basically gives the green light to cheating and exploiting. I think they've let us all down on this one.