Switching languages every 3 months does not sound like a way for most mortals to get a lot of concrete things done, although perhaps you will have a payoff of knowledge after several years, assuming you do not already know several languages.
Most mortals will end up with some half-baked newbie projects and a huge long list of languages they have used, apply for jobs and find that any given job is really only interested in one or max two blub languages
Indeed, academia rewards this kind of technique focus, in large part because academia is not much about truth and more about making a name with sexy stuff, connections, writing big grants, etc.
And also, Python, Riak, Redis. And these are only the tools that I did use with great success.
Others are PHP, MySQL (and other *SQL), Java, C#. Of course, once I found out that they are "no good" for finding new exciting problems to solve, I dropped them, so I didn't become a "master" of them. With the exception of MySQL, which I think I am a "master" of.
EDIT: also, I never claimed that 3 months is the magic number. It was a (wild) guess by someone else.
Second Edit: Also, for quite some time I have been studying C, Haskell, Lisp and to lesser extend some other stuff. I am already quite familiar with the type of problems they shine at. Once such a problem emerges, I will readily jump on it, and will intensify my learning of the tool in question.
Most mortals will end up with some half-baked newbie projects and a huge long list of languages they have used, apply for jobs and find that any given job is really only interested in one or max two blub languages
Indeed, academia rewards this kind of technique focus, in large part because academia is not much about truth and more about making a name with sexy stuff, connections, writing big grants, etc.