Did Chazal ruin Biblical Judaism or improve it?

One often hears in MO (and more specifically LWMO) circles about how Chazal darshened away some of the more egregious aspects of Biblical Judaism e.g. Ben Sorer uMoreh, the various death penalties and such. However from another angle, Chazal took Judaism in a worse direction than the Biblical writers. The Neviim were huge proponents of social justice (or were made to appear so), with various famous passages proclaiming how God hates avodah and mitzvos and just wants basic justice and kindness. Of course Chazal were not against justice and kindness, but with their emphasis on halachic minutae it seems that the Neviim's message has gotten somewhat lost, and this is reflected even today with the Chareidi emphasis on halachah and chumrah as opposed to basic morality and care of all humanity,

Trembling before Chareidim

I noticed someone recently posted a blog about how people in the Chareidi community live in fear of being labelled not sufficiently frum enough, and how happy the author was to be in Modern Orthodoxy. This is funny, considering that in my experience, nobody is more fearful of being honest about their true beliefs than educated Modern Orthodox Rabbis. And RWMO live in perpetual fear (or maybe concern) that the excesses of the LWMO are going to delegitemize all of MO before the Chareidim. Everyone looks over their right shoulder. I guess you can claim that the MO Rabbis just want to hold onto their jobs and status, so it's not really fear per se, but rather just being practical, kind of like not being rude to your boss, even though you want to. Whereas in the Chareidi community there is actual fear, because coming out could ruin your life. Could be.