For the company that is, as you noted, high-demand the hiring market is a buyers market - they get to choose who they want, and they have ample supply of candidates. The natural motivation for them is to choose a candidate that would be most profitable for the company. Now who is better for them - somebody who doesn't have a life outside of code and would obsessively invest his time into cool projects the company throws at them - or somebody who does his part but clocks out every day at 5pm sharp (I am exaggerating but you get my point)? Now, it may be that the latter person is way more productive than the former - but the reality is that you rarely love to do something that you are bad at, so usually they can hope that person that codes a lot for his personal enjoyment is reasonable good at it. It's not always true, but it's a good heuristic and a big part of hiring is about finding good heuristics that would predict your future usefulness for the company. So yes, I think it is inevitable that you will be getting lower marks on whatever scale they are using in Google or likes than somebody with a lot of hobby projects. That doesn't mean you won't be hired at the end - but it must reduce the chances compared to other candidates.
But this is the time you need to ask yourself if you really want to play by these rules? There are a lot of companies that are positively starved for good developers, and many of them are ready to offer you very good conditions and be completely content to get you only for 40 hours a week - provided that you are a good developer. They don't have Google's glamour and fame, so they can't be as picky with talent. Sure, you are taking a bet - some of them might be next Twitter or Linkedin, some of them would forever be a footnote on the dusty pages of history, some of them would be neither - just old boring regular business. But a lot of them desperately need good people to work for them, and it's sellers market there.
So the decision is - which rules are more fit to your lifestyle?