Not sure if it's a joke or not...
work on your "being a guy that a CTO would want to have a beer with"... is probably not the best advice.
Starting a startup and failing doesn't look bad in your CV, don't worry about that.
But if you are looking for a job, you should definitely work on your technical skills, learn new technologies etc instead of your networking skills...
Well, you should work on your technical skills because that is the right thing to do and because it helps you in the long run, but the parent poster is obviously right - if you're looking at the effect on actual hiring decision the networking skills will have a larger effect anyways.
Spent 3 years becoming an expert in technology X? Even if the whole job offer is about X, you'll have only slightly better chances than the guy who had a glimpse at X 3 years ago - the interview process simply has no way to find out how much better you are at X.
But if you were at a final round with a few other qualified candidates (maybe better qualified than you, maybe worse qualified - noone can tell, they can only tell that they're qualified) - and you're 'the grumpy one' or someone else has a good emotional contact - then that will be a decisive factor. Even if the decisionmakers deny this; and even if the decisionmakers are informed about such biases and actively try to counter them - research shows that they still do decide that way, it's simply human to do so.
Completely stupid irrelevant factors (such as being taller) do have a relationship to the offers you get and how much people are willing to pay you. That's how life works; ignoring it won't change it; denying it won't change it; saying that it's not fair (it isn't) won't change it - you may just learn about it and try to exploit it. And 'work on your "being a guy that a CTO would want to have a beer with" skill' is solid advice on how to try to exploit how reality really works.
I don't think it's a joke at all - I know lots of companies and people (myself included) who stress their culture and fit so much that technical skills often fall by the wayside. Sure, we want to know if you can code, but that can usually be figured out with a 15 minute white board test. If you're truly a pain to work with, unable to work in a team environment, or generally not collaborative, you probably won't get a job at my company.
Conversely, if you're a self-motivated learner, a good team member, and able to contribute, but don't quite have the technical skills we're looking for, we'll gladly take a training hit (usually 2 to 4 weeks) to get you up to speed on language X in exchange for an engaged and valuable employee.
Well, as you say, you do check if they're "good people and nice to work with" - the post said pretty much that, because "being the kind of person I'd like to have a beer after work" is pretty much the same emotional reaction as "being the kind of person that is good and nice to work with", and isn't related to the fact if you're actually having beer after work with anyone.
> work on your "being a guy that a CTO would want to have a beer with"... is probably not the best advice.
It may be if you consider that the CTO would probably like to talk about interesting technologies, new programming language developments etc. over that beer. In other words, getting genuinely interested in your occupation will go a long way when looking for a job.
Starting a startup and failing doesn't look bad in your CV, don't worry about that. But if you are looking for a job, you should definitely work on your technical skills, learn new technologies etc instead of your networking skills...