It's because the certified like new process goes through a 100+ point inspection, but for the most part, it won't cover the issues that most thunderbolt users are having. that's why some people here have had several returned phones. in fact, my replacement phone had more issues than my original, so i just returned the replacement.
Yeah, the 100 point inspection is garbage. It goes like this:
1) Does the phone have a microphone hole?
2) Does the phone have a speaker grill?
3) Does the phone have a power button?
4) Does the phone have a volume up button?
5) Does the phone have a volume down button?
6) Is the power button damaged?
7) Does the power button depress easily?
8) Is the volume up button damaged?
9) Does the volume up buttom depress easily?
10) Does the volume down button damaged?
11) Does the volume down button depress easily?
12) Is the bottom left screw under the battery cover present?
13) Is the bottom left screw tight?
14) is the middle left screw under the battery cover present?
.............and on and on and on.
It's like when you go to Midas and they perform a 129 point inspection on your car...and it takes 90 seconds. It's a complete joke.
It would be VERY interesting if people took the time to track the serial numbers on these replacements. I guarantee everyone I have sent back got sent on to someone else, and everyone I was sent was first returned by someone else. We're all getting the same phones, just playing round robin. That's why I finally demanded a brand new phone...and it's perfect.