Thankfully this is limited to a single (and seemingly small) company's hardware, rather than the entire SSL/TLS stack. Glad it wasn't someone like Cisco too ...
True, but F5 is still extremely popular with medium and large companies.
We had session tickets disabled already so weren't affected, but you'd be surprised some of the sites that use these devices. I believe AT&T has quite a number in use.
At one time Azure was built on a whole bunch of F5s. Unsure if they are still in the picture.
F5 is just across the water from Microsoft, and there is a lot of cross-pollination of employees between the two. Even if F5 wasn't the best choice, I wouldn't be surprised if they were used just due to familiarity.