This.
I worked for them over a holiday season as a "driver helper" once, and the whole experience was pretty eye opening. Pretty much every package is "shipper release" if it's residential. A lot of good drivers would tell me that if it looked expensive (laptop sized box from Best Buy, for example) that I should try to get a signature even though the package didn't require one. But basically, drivers don't need to get your signature anymore. They should still try to deliver something, but if it's 3pm in the afternoon (the routes are designed to have them doing residential in the evening, but if they have an easy day...) they are going to assume no one is home, and might make the bad choice there. UPS makes all their money from commercial stuff anyway, residential is just a side thought that is a total pain in the ass to deal with.