Left Coast, what you're not taking into account is how God deals with people by increments through the ages he slowly but surely unveiled more revelations by the prophets. The Bible was literally given over a span of centuries and even millennia. Each prophet adding some new revelation. So, when the Israelites originally came out of Egypt they were a pretty typical Semitic bronze age culture. I think you expecting them to suddenly have a revolution where they immediately embraced emancipation is quite unrealistic. Considering that it has taken mankind as a whole all this time to embrace the same idea.
If we assume that the Torah was written by men, then I do hear where you're coming from and it's not at all surprising that the Israelites would keep slaves as many societies did at the time. Like any other writing, the Bible is a human product of its time.
The problem is, fundamentalist Christians want us to believe that the Bible is actually from their morally perfect God and contains no error, factually or morally. So when we're dealing with an omniscient, omnipoten, morally perfect deity, I absolutely do expect him to condemn slavery. If he instead condones and even commands slavery, that is a major moral shortcoming. Arguing that he just couldn't tell the Israelistes not to own other people as property because it was commonplace is a little silly given the other things Yahweh commanded. The whole point of the Torah, per the Torah, is to distinguish the Jews from the surrounding pagan cultures by commanding them to live differently in a variety of ways. It's really not that tough to say: "Hey guys - don't enslave people. It's bad."
I believe God was working with them and the Law of Moses itself is not only a spiritual/moral Law. It was also very much a civil law code for the time period. Governing every aspect of bronze age tribal life. So the issue of slavery also had to be covered for civil reasons. This does not mean that God condones or approves.
If you command someone to do something, or tell them the proper way to do it, that's condoning and approving. Think through this. If I tell you the proper way to bake a cake, is that condemnation of cake baking? No, of course not. I would never tell you
how to do something I had a major moral objection to.
So, God was dealing with the Israelites and slowly bringing them into righteousness. It was probably inconceivable to over throw the institution of slavery in a bronze age culture of the time.
Nothing is inconceivable for an omniscient deity, is it?