Side note: I don't really care about a company's business practices (unless they directly affect me), I don't care how they treat their employees, I don't care if they punch babies, or any of that other crap. I care about the products they have, the price I'm paying, and my experience dealing with the company. But I will answer your question based on my understanding and my experience.
1. Walmart leads, other retailers follow. Walmart has the power to make their suppliers do what they want, because losing Walmart is huge. Walmart makes its suppliers continually lower prices, and they do. This has had positive effects in increasing efficiency. It has also had negative effects in decreasing quality. Both of those effects carry over to other retailers, including Target.
2. People will give you anecdotal evidence to the contrary, but in general you'll have a more pleasant shopping experience at Target. The stores are nicer and cleaner (case in point: go to the spray paint section in any Walmart). Targets are usually less crowded, and the customer are, to put it bluntly, from a higher economic class. That's not an assumption, that's a fact. The average Target customer makes $10k/yr more than the average Walmart customer. Walmart knows that, and they've been working to improve. Have you noticed that over the last few years they've been putting hardwood (or maybe laminate) floors in their clothing sections? That's because clothing is one of the areas where Target beats Walmart, which draws in the customers who make more money. Is that elitist? Yeah. Is it ironic for an elitist to shop at Target? Yeah. I'm just stating the facts - one of the reasons people shop at Target instead of Walmart is because it's a more pleasant shopping experience. I don't really care if your local Walmart and Target are the opposite, because apparently that's not the case in most places.
So yeah, the stores a similar. But there are things that differentiate them, and those are the reasons people shop at one store or the other. I shop at both, but more frequently at Target. Walmart is closer, but Target is next to Costco and Home Depot.