Velitation

I'm guessing Tencent is expecting Reddit to eventually make a IPO on the stock market. Could be very lucrative for them in the future. Otherwise I don't really see why else they put that much of an investment in.

From what I remember, Valve usually only takes in industry veterans, with one notable exception being some students at DigiPen making a game that Valve wanted to improve upon, which became Portal. You don't necessarily need C++ to do that, you need to know the fundamentals so that you can continue to learn throughout your career because the industry changes all the time. If you want Valve to notice, then you're going to need to make a game that gets their attention. You're going to have to learn it on your own time though. Anyway, good luck with your studies.