...but it has enough mass to accumulate these guys...
...and if Alan Stern thinks it's a planet, then it's a planet. I like his explanation, which basically says the scientists were driven by memorization fear than science:
...Nowhere else in astronomy is there any definition that was specifically engineered to limit the number of objects to something that you can memorize... "when the world was quaint, and our knowledge was limited, and we only knew of 9 planets, you could know their names...then scientists...said 'this will tarnish our reputation, you know, school children won't be able to remember them...you know what I said? 'we're gonna go back to 8 states now?'...
Stern says "a planet is an object in space that's large enough to be rounded by its own self-gravity." That works for me.