Ehtyar, I think the issue here with using "denial of service" is that we usually hear it in terms of DOS or DDOS attacks, and not just bugs. The way it's used here sounds like if I wrote a program that sometimes ended up going into an infinite loop without an escape and locked up the program, that would be considered a "Denial of Service." And while that may technically be true (I don't know if it is or not), we've always just called those "bugs" or "infinite loops" or "locking up" or something similar.
In other words, "Denial of Service" has a very negative, malicious connotation associated with it because of how it's frequently used by "bad guys" to do bad things. Kind of like how the general population thinks the word "hacker" means a malicious person trying to do bad things with computers/electronics.
And I agree with mouser and others: Whenever Acrobat opens in the browser is practically denies my browser service because it freezes it up or takes forever to initialize or whatever. Acrobat opened up independently of the browser is okay--usually--but whoever decided Acrobat should be a browser plugin needs to be punished!