Hindu dharma nowhere recommends segregation and division based upon caste. First off, caste is profession based. It's the con-men in hinduism who took advantage of caste system for their own benefit. And people do not be premature to stigmatize hinduism only: look how many gypsies are killed even today by so called civilized Christians in Europe. Do you give any F@k about that?

Just started reading Bhagwad Gita, it's awesome. It explicitly says one who does not have any Vedic knowledge is sudra. A bahun is sudra if he lacks Vedic knowledge, a sudra is arya if he possesses knowledge of Vedas. So, where is hinduism disparaging lower castes? A bahun is bahun by birth, that's problematic and it should and will change with time. 

BTW, I do not think castism is that bad in Nepal now compared to was 10-15 years ago. It's just a matter of time before castism becomes non-existent. Do not blame and wait for others, if you want to change the society why not to start from yourself? Just start to marry and intermingle with so-called lower castes. If you can't and still rant about castism you are a sore hypocrite. Discussion like this should not exist.