I would argue that all of these things matter. It would be naïve to assume that appearances and persona do not matter to your career, regardless of whether or not it should matter. I am not advocating being false, but maintaining a professional LinkedIn profile would likely help your chances. Yes, some companies might prefer someone with no profile, or a very limited one, but even a tight-lipped presentation - hypothetically preferable to hedge funds and security companies - should still be professional, with a solid picture and some indication of ability. Can you advance your career incorrectly? Obviously, lies and misrepresentations are 'incorrect' but LinkedIn is no less credible than having a good resume, GitHub repos, blogs, and websites. Yes, some of these things will not advance you internally, but not doing some external work closes one off to a range of possibilities.

Minor point, although alternative universe sounds like an insult, it is true that we live in different spheres, with different perceptions, a personal alternative universe. - Does web persona matter? - Do you want to advance in your career? - Do you think networking matters?

I am not job hopping at all. My current employment is so far 2.5 years, which started as contract, but then hired. Before that, contract employee for 3.25 at UBS, and before that contract 2.25 years at Deutsche Bank. Recently, the CIO of the company I work recently connected with me via LinkedIn, and it is often the first place I go to connect with colleagues. I can look at someone's background before I talk with them to understand them better. Regardless of the recruiters, it presents your professional place in the world, even if you are a long-term perm employee. Some people will inevitably check out your profile and that will reflect on you. If you want to move beyond being a software engineer, it likely pays to groom your web persona. Do you want to get found by someone that wants you as architect or as lead or as development manager, which in terms of title is the step above engineer? Clichés about networking aside, contacts and presence still matter, both internally and externally.

It is hard to say where recruiters find my profile, and then decide to contact me. I am contacted frequently by recruiters for jobs via LinkedIn, and it is one of recruiter's favorites, according to surveys. I looked at my last two (2) job's email trails and neither indicated from which source the recruiter found me. Even if I cannot pin down from where the recruiters, or their automations, found me, it would be ludicrous to not have a strong presence on LinkedIn. I have numerous online profiles - some of these I use personally as well as for career persona - LinkedIn, Monster, Google+, Twitter, FaceBook, Indeed, etc., and I would be hard-pressed to guess, but if you wanted to be found, LinkedIn seems essential, judging from the amount of email I get from that site. As for others, I do know of one person unemployed from the real estate mortgage industry for several years, that once he was on LinkedIn, friended or was friended by several thousand people, was employed and moved out of his girlfriend's apartment in a matter of weeks.

Pardon if this thread start is satire. Because of years I spent developing tactical software in VBA and SQL, I found it easy to first convert to VB.NET and then C#. Not you personally, but if you cannot program in either, I find it funny, and privately think less of you, although one must consider the language barrier as an explanation. And I have met people that can only code in one, but because no one in my world codes VB.NET, it always happens to be C# people. A platform is a platform, and although there are some idiosyncrasies, the bulk of code can be written easily in one as the written in the other. Also, please note, the VB.NET demand, according to Tiobe's index, is increasing, although my guess its usage in buried under ASP.NET and related technologies.