Like most people who have not studied the subject, you have gone with "sound bites" highlighting the negatives without any context thus distorting the whole discourse. In the interest of "personal edification" i suggest a study of the following;
Do you know that there are many texts called "Dharmasutras" (your cherry-picked quote is from Gautama's)? Do you know how the concept of Varnas began, debated, evolved and interpreted from ancient through medieval texts? Before the later texts there was no ideology of fixed Varnas but only a mapping of the concept of "purity" to something called a "Varna" i.e. the idea of a rigid "Caste" did not exist. It was a cultural manifestation during a certain period which had unfortunately propagated and later taken as the "truth". A careful study of Hindu Dharma texts would reveal the fact that it was never a single "ideology" like Islam/Christianity but a constantly evolving system of ideas towards a better Society.
I highly suggest reading Prof. Patrick Olivelles's paper "Caste and Purity: A study in the language of the Dharma literature" to really understand the issues involved.
PS: Wendy Doniger is a hack. Anybody who interprets thousand year old texts from a different place and time using modern sensibilities cannot be considered a "Scholar".