Agreed. It's very difficult, and sometimes impossible, to retrofit security, especially without a huge investment.
If you just don't even care enough, then you'll never get it right. Not saying that Ubiquiti is that way, but there's a reason why some companies never seem to have significant security concerns and others have an unrelenting stream of them.
Unifi is one of the companies with awesome potential but they just seem to whiff it constantly on security and software.