That is what I have a cannot understand. Even today, after so many years, it seems you can put whatever you want in url destination on a keyword level.
Few days ago, I was testing some tracking tool through ad with keyword that would never be typed by a real user. At some point I changed destination URL, but not the display URL (in ad text). A day or so later, I got disapproval.
So, Viva Google! it worked, and I was happy for it.
Still, I see that folks that do it intentionally, almost always do it on keyword level which seems to be working for them, very well.
Out from this, we end up spending time in figuring why we suddenly pay more than on previous days, and spend hours on chasing those, reporting them, and then going through frustration of waiting for results.