It's kind of pathetic that Arrington labels startups who demoed at TC50 as a "TC50 startup" .. Slyly attaching his name to every startup that sucked up to him enough to get onto the demo roster.
Of course it's not the same, but in both cases the writer is using a short phrase to give context about the company.
Participating in TC50 is not as prestigious as participating in YC, but it is not trivial either. As a reader, I care about whether a company launched at TC50.
To be honest, I don't. I don't know 100% how much mentorship input assistance advice, etc TC50 give, but it seems likely that YC or any investor give far more.
The "TC50 startup" thing just seems a bit like newspapers who constantly feel the need to remind you that they broke certain stories "As previously exclusively reported in this very paper" etc.
Just because someone launched at a certain venue, doesn't mean that venue can really claim any ownership. But then it's a common enough thing - you get stars/singers/actors who are constantly labeled as 'being discovered by X' which must be pretty irritating for them.
Demoing at TC50 isn't really that prestigious. It's kind of gross actually. Last year's was bizarre, starting off with the star spangled banner being sung by attractive female founders made me feel somewhat dirty just being there. Then the companies.. Totally squicky. Hangout.net was one of the companies who couldn't stop saying "increase branding opportunities to children with product placement" over and over again. I imagined their CEO with a barbell mustache and a maniacal laugh every time he talked about putting Nike and PepsiCo logos in the game, and letting children buy those with their milk money and allowances. It actually made me want to never allow my daughter to use a computer.
To quote the Clash,
"If Adolph Hitler, flew in today..
They'd send a limousine anyways"