To be fair, there are harsher sounding dialects. I have been deducted points in speech competitions for my Eastern accent; my teacher was Czech. There are softer dialects where the ch is almost an sh and growing up my granny spoke low German which is not very harsh-sounding to my ear at all. (Probably because there was often Dutch mixed in?)

I don't consider German to be the most musical of languages (unlike, say, Spanish) but on the whole it isn't as harsh as people stereotype it to be.

I think Chinese gets an unfair rap in this regard, as well. Some dialects sound quite harsh but others are soft and swishy.

Same with English. Some English dialects are harder on the ear than others.