So your issue is with the quality of the firmware on the devices and not the fact that it is a camera in a private place which is connected to the internet?
I agree with everything you're saying, but you may be overstating security patches. Until recently, most Android phones only had a few years of security updates.
I guess what I'm getting at is that if I truly believed in keeping Internet connected cameras outside of private areas I wouldn't have a smart phone at all.
The problem with Teslas wasn't the firmware on the cameras, but rather the infrastructure behind it. Ideally the data would be encrypted on servers and decrypted locally when needed. This doesn't pair nicely with services that perform analytics on video streams, of course, but it's a better option for privacy.
At the end of the day I share your concerns, and I want only devices which are controlled locally. I have been making efforts to make this a reality.