1) It's a bit of an absurd to expect a "warning" from DJI about third-party batteries, since they already recommend to use their own ONLY to begin with, and take some steps to ensure it stays that way. So it's clearly and expressly implied from the start, isn't it?
2) P3 batteries aren't "just any battery". Without entering the merits of cell quality or occasional issues, the "smart battery" is part of a system designed and engineered to work in a specific way, and that includes the update of the "smart" part of the battery to go along the function of the entire system in better and safer ways, whenever DJI thinks it's in good order to do so and for whatever reason. Is there something wrong with this or is it just me?
3) That's different from a car or other device, and even from open-source starter kits drones. I've got lots of different LiPOs for all my devices (bike lights, copters, cars, planes, etc.). Some work fine with any kind/brand while others don't (Lupine for instance). What I'm trying to say is, the good comes with the bad. Some stuff accept third-party parts and accessories but others don't, for different reasons. And we're free to chose which way we go. But once we go, the right thing to do is to stick to instructions - unless you know very well what you're doing (then you can get the good with the good sometimes) AND/OR accept the consequences of your choices. I don't get it that for some people "following instructions" is wrong, stupid or sheepish.
4) A quad like the P3 isn't just a quad. It's a consumer drone, designed and engineered in a way to be easy, instant and accessible flying camera with relatively simple maintenance. That brings compromises, and the use of some smartness in the battery is perhaps the most obvious of that since the power source is a big deal in any RC device. There are lots of open-source start kits on the mkt, a few even from DJI, for those who don't like to be tied to a single brand or source for parts and are into DIY.
5) I understand that people feel fooled by DJI in many ways when something like this happens. DJI is big corp, everyone hates their kind. I for myself feel fooled by sellers who advertise "like the original" when it's not and that causes some problem along the line, especially when the manufacturer of the quad makes it very, very clear that you use their own stuff only. So DJI is evil for trying to stick to their business, and third-party suppliers are good for making theirs out of breaking DJI's system and collect the money of people who don't like to follow instructions and are looking for saving a buck on props, batteries, etc. Right.
Well, it's everyone's choice to go against the grain and take chances - just not fair to blame the manufacturer or come up with conspiracy theories. DJI is in the market to sell drones, batteries and accessories, believing otherwise is just plain wrong. Anyone is entitled to save money, but putting the blame on the wrong part isn't going to solve anything, for us as consumers and for the companies as well. As consumers, we should get informed, make our choices and live with them, for our own benefit.