I think what may be more important is what disqualifies someone from being a lolcow. There are lots of people who would be lolcows except for one thing, like they're really nice, they are successful celebrities, or whatever.
Success really seems to be one of them, even on a minor scale. Someone can fall hard to the point of ending up a lolcow after some success, but they're generally not a lolcow while successful.
The Metokur thread strikes me as an example of this. He's done some good shit, he's done some dumb shit. He's chimped, ragequit, and has some cringy opinions.
He also did some hilarious work on Nick Nyberg and Nick Bate and on tumblr SJWs. Frankly, if he'd done shit at that level here on this site he would be considered a site hero.
And now he is the subject of not one but two (one locked) threads on how he isn't a lolcow.
I'm in the middle on this in that I think he's a bit of a lolcow but not much of one.
Lolcow is a matter of opinion. It should be more that you're laughing at them than that you're mad at them and consider them the reincarnation of Hitler.
The laughter should be because of their failure, not because they're succeeding, to whatever degree, at something you hate.
Wu is an example of a lolcow. That recent panel where nobody showed up is a great example of why. But the fact that there's a TV show, even a ludicrous one, actually about Wu could arguably be a "success" of sorts, even if she's on the same level as someone who pissed in the meat at their job at Taco Bell.