Don't worry I didn't take it that way at all! But yeah, I've had a whole bunch of terrible experiences with mail carriers. It's extremely consistent in SoCal, they typically don't care at all. During christmas they leave packages on wet lawns, literally throw packages, etc etc. Of course Im in so cal, so we have a metric ton of people.
UPS seems to be the worst in my experience, and they're the ones who have marked late deliveries as "on time", been caught throwing my packages, delivering things without any confirmation, etc etc.
I gotta say, I've never had the delivery confirmation signature matter with any mail carrier. From people i've sold things to to items i've purchased -- USPS, UPS, FedEx -- Not one has actually gone through with the signature in my experience.. I've even had packages I've paid for Delivery Confirmation for in sales stolen when they were left on the porch.
So i'm glad you've had better experiences. But so far I've had nothing but bad experiences. I could write pages and pages full of my experiences. From mail carriers yelling at me, telling me they "left my packages to teach me a lesson" (long story short, I had a sore throat and tried to tell the mail man from across the street he forgot my outgoing packages. I guess it sounded like I was yelling at him so for a few weeks the local post decided to 'teach me a lesson'). I can literally go on, and on, and on.