I'm going to partly agree with you here. Yes, the main point of the DP is for devs to test new code against to watch for bugs, as the subsystem on 8.1 will not be changed accept for big fixes.
On the other side, I feel that it's a PUBLIC beta test, as I would say about 95% of the people on here who installed DP are NOT devs. If Microsoft wanted this to be just for DEVS, they would of locked it down to past devs who have released apps in the past, and lock it down. They do this type of stuff all the time.
This is the same crap again, people seem to complain about everything, good or bad, it's just human nature. Maybe Microsoft should of not released this publicly like they did, and make us all wait till our carriers release it ? This was the program that Microsoft said they would do when WP8 was announced, people complained when it didn't happen, now it did, they get a little buggy code and they hate Microsoft.
People need to get over this, Yes, No matter what Microsoft says, the DP is a pubic beta test, to find all the little issues and hear the feedback. This is the best way Microsoft can work through all the bugs found (note a few update so far because of the issues) to make WIndows Phone as stable and solid as possible. If you know anything about how development works, when you believe you have final code, you want to get it in as many hands as possible to debug the issues, this is so you can hear what people like, and what people hate and change what code is needed to fix possible issues, so when the final hits, it will be almost 100% bug free because everyone found it.
With this being said, Once the final is released from your carrier with the phone firmware, AND you still have problems, then you have every right to complain. You signed up for software with some possible unfinished code, and this is what you have right now...
So, everyone, shut up, deal with the little issues, WHEN YOU GET YOUR FINAL version from your carrier, Then you can complain.