(UTC) 
 :::::I think it is fair to state that no traditional Swiss German dialect is inherently mutually intelligible with modern Standard German. In other words, Standard German speakers cannot understand Swiss German any more that they can understand Dutch, or that Londoners can understand Shetland Scots; in fact, many Germans even mistake Swiss-German-accented Standard German (which is absolutely intelligible) for Swiss German dialect. While Upper/Central German certainly used to be a classical dialect continuum from the Old High German period until some more recent period, which is, however, difficult to determine (a German Wikipedian knowledgeable on Low German dialectology has emphatically rejected the traditional view of transitional dialects connecting Low German with Central German and other forms of West Germanic still in the 19th century, pointing out that no such transitional forms are actually attested and the language boundary is quite sharp), by the modern period the divergence between the various region forms of West Germanic spoken in Central Europe has grown so large that it seems more appropriate to speak of a language family (partly) united by a Standard German Dachsprache. Moreover, within West Germanic, the Upper–Central–Lower (or even Upper–Central) German block does not appear to form a unitary branch, so from an objective linguistic (or at least not sociolinguistic) point of view the folk concept of a "German language" comprising all Upper and Central (and, for many, even Low) German dialects, which lies at the basis of the idea that "Swiss German" is "simply a German dialect", is untenable. Swiss German in any of its forms is not even functionally a mere "dialect of German". 
 :::::We see the same political bias and historical-ideological baggage at work here that drives the concept of English (including Scots), Greek, Arabic or Chinese as a unitary language rather than a language family, or such (revealing) extreme cases as the occasional claim that English is but a "corrupted" (presumably by French) German (or sometimes Scandinavian) dialect (which would be an illogical concept even if Germany or some Scandinavian country had conquered some or all English-speaking regions of the world and outlawed the use of Standard English) or Kurdish a "Mountain Turkish" dialect. (If a speech form is so "corrupted" that you cannot make heads nor tails of it, the logical conclusion is that it is simply not the same language as yours.) Nor can a language suddenly become a dialect, or vice versa, due to purely political or social forces and changes (compare the cases of Occitan, Dutch and Low German, for example; Upper German too used to possess at least an emerging written standard before that one was ousted in favour of Standard German). Just because a language is not an Ausbausprache that does not mean that it is not a "real language". 
 ::::::So, in any realistic sense, Swiss German is a completely different language from the language taught as "German" in schools and universities. No wonder you understand nothing! And same for Scots. If you cannot even understand Scottish English well (I know I can't), or whatever these people were really speaking, who are you to engage in linguistic imperialism and deny the deep differences between Scots and (Standard) English? 
 ::::::Of course, you can reject the artificial and arbitary language–dialect distinction utterly and completely, but in practice this is less easy than in theory: even well-established linguistic concepts such as language family or language isolate make little sense without it, and "genetic unit" is a bit too technical-sounding for general use.   21:26, 10 November 2014