Antr, you gesture to "substantiated, well supported, warrants/subpoenas/etc" but fail to ask the more relevant question. Private banking enterprises within Switzerland have provided tax haven services for U.S. and European capital for many years, beginning in the post-WWI period when tax competition was minimal. The 1920s and 1930s were halcyon days for global capital fleeing the warring nations. Switzerland had a lightweight and liberal government, and banks had an appetite for alien capital when few others did.
Quoting Farquet 2012:
In a subordinate position before the war, notably with regard to the competition of France and Germany, Swiss bankers took advantage of the new international context to affirm themselves as figures of substance in the financial world at the beginning of the 1920s. Although, for example, the cumulative balance sheets of the major Swiss banks represented only 26% of those of their French counterparts in 1913, they subsequently amounted to 73% in 1929.
The Swiss financial centre was particularly renowned in the sector of cross-border wealth management. In fact, foreign capital flowed en masse towards the Swiss haven in the interwar years. According to a [League of Nations] report, owing to the importance of foreign assets, in 1929, Switzerland possessed by far the highest per capita total of bank deposits in the world. The lack of a reliable balance of payments, as much as the absence of the legal obligation for Swiss banks to publish details regarding their accounts, nevertheless prevent an exact estimate of the total amount of imported capital. Banking balance sheets indicate a general trend, but are inadequate sources.
A committee of experts working on Swiss history during World War II who, exceptionally, had access to the in-house archives of the banks, showed that holdings of securities, generally in off-balance-sheet bank custody accounts, represented, in the two biggest Swiss banks in 1931, more than three times their balance-sheet.
[http://www.ehes.org/EHES_No27.pdf]
End quotation.
Needless to say, the confiscatory tax rates in the U.S. during the late 50s and 60s made going after Swiss accounts attractive. But the Swiss were having none of it.
So are the two situations you mention genuinely at opposite spectrums? Or is Switzerland's special brand the product of a persistently muscular political consensus that, after more than fifty years, may now be flagging? And if the latter is the case, then the OP asks a fair question.