When NZ adopted MMP (proportional system similar to Germany's) both the major parties (National & Labour) campaigned against it on the "better the devil you know" basis, which the electorate see through. The first MMP election was mildly rubbish, with a populist kingmaker gaining disproportionate leverage, but since then the electorate has been shrewder and in a subsequent referendum MMP remained the preferred system.
I'm not being serious, but at least in the UK one of the major defences of the British system whenever electoral reform is brought up is, "it's the oldest so it must be the best".