I think the problem is that it allows folks to build off an existing brand name.
I'm all for good competition, but I do still think we need unique branding. And I don't think you can expect a company to buy every variation of every URL that uses their name brand.
For example... if I created a new softdrink, great. Maybe I'll rival Coke or Pepsi. But if I call it PepsiCoke, that seems like I'm just cheating them.
"Greatness is not a function of circumstance. Greatness, it turns out, is largely a matter of conscious choice, and discipline." - Jim Collins