Good god, what would militant anti-christian zealots ever do without the Old Testament? They almost never complain about the New Testament. If it bothers you that much why not find some Jewish neighbors or coworkers to complain about it to? It was the Hebrews who wrote the OT.
As far as I know, God himself rarely ever directly talks in the OT, outside the books of Torah. Elsewhere, it seems to be mostly Jewish prophets and kings claiming to speak on behalf of God.
Much of the OT was written or compiled during the Babylonian captivity. You can understand why the Israelites could imagine a wrathful God who is open to retribution. People who are being oppressed rarely think of sugar, spice, and everything nice. I doubt Israelites wanted to sing Kumbaya with their enemies and oppressors.
The OT is almost never used in the liturgy of the Christian traditions I am familiar with. The New Testament is considered the final revelation and a superior revelation.. Just as importantly, the majority of world Christianity does not consider the bible, and in particular the OT the sole authority on religious belief. Church teaching, ecelesiastical authority, and Church tradition have equal authority and equal standing to the bible in Christian belief.
You seem to have based your opinion of Christianity on the fire and brimstone Protestants in America. American Protestant fundamentalists are a small minority of world Christianity.