What a chance to bring this thread on top again I don't agree - "Swiss German" (to be correct: Alemannic) and High German are two independant languages, one only has little to do with the other. Which has been said here about a zillion of times. For business use or in order to read books and newspapers, you might be correct. If you however want to integrate into the Swiss society, Alemannic is an absolute must. Now decide/chose what is more important to you.
I don't think so.
a) Swiss German, just like any other Alemannic dialect, is fairly closely related to Standard German.
b) Without Standard German you don't get anywhere in business. You cannot write a simple letter, and you cannot talk to anybody outside the Alemannic areas.
c) Without Swiss German you can still integrate into Swiss society. Those that do not accept you because you do not speak Swiss German are not worth any effort whatsoever. They are jingoistic morons.