Well, so far it seems that the various data already purchased yielded some revenue. Plus, there is the scare-factor, that can make the tax evaders either shift money (which is not as easy as it sounds, or the Swiss banks' accounts would be empty by now), or go legitimate by making amended returns. Of which there seem to be more than a few recently.
There is no guarantee that the little bits will make one big fat juicy cake.
As I said before, it is not that easy to transfer the money, because we are talking about individual wealth, and not some international investment fund. The wealth may be in such a fund, but it is accounted for in a bank (usually). The transnational investment fund may shift money easily between tax heavens, the wealthy tax evader not.
Even realpolitik needs to be based on some legitimate claims, otherwise it will fail in the long run. If you undermine the legitimacy of the German taxation system with such deals, the repurcussions can be much more severe. If I would pay income taxes in Germany, I'd already be pissed off that I pay more on my labour-based income, than some other guy on his capital gains. Now reward tax evasion, and you'll see me trying to evade taxes as well. Get it? Btw, the realpolitik is that taxes in Germany are already comparatively low.
I guess you'd never have voted for them to begin with. Btw, we don't have socialists, we have social democrats. And no, I voted for neither. Based on them blocking this deal, I might consider doing so
