Out of all the unsubstantiated what if scenarios and other such in this thread, I take the following:
1. Good system design should preclude malfunction from 'random' or corrupted (intentionally or not) data.
I agree wholeheartedly, a no brainer, but we all know there's that one in a million, billion, whatever, combination of input that can cause an issue. Sadly software is rarely 100% verifiably bug free.
2. No system can be entirely fault free unless it's so simple it's possible to prove operation for every single possible instance of presented data along with every possible environmental influence.
My take on this:
The nature of my job means that I can be many miles from home at stupid times of day and night, thus I have been in situations many times where I've needed to buy random pieces of computer hardware from vendors I would not normally use to perform job function, on at least a couple of occasions I've had to buy USB-Serial adapters (things go faulty, get mechanically damaged, lost, etc.).
When I'm two hundred miles from home at three AM in the morning with people in positions of genuine, government mandated, authority asking me how long something is going to take to repair, I do not want to explain that my serial dongle doesn't work because of someone acting like a 2 year old and having a hissy fit which may or may not render the USB dongle bought from their local 24 hour supermarket unusable.
So, I avoid FTDI unless it's absolutely unavoidable (I.E. built in to a larger product).
Not a huge loss for FTDI, not even the price of a sandwich at lunch time but the tiny drip drip of water erodes much larger mountains than FTDI.
Shortsighted and childish of them.