I suspect the "X" branding for these companies has less to do with Roman numerals and more to do with the prominent use of "X" in mathematics as a unknown variable, and that's due to René Descartes according to:

https://hsm.stackexchange.com/questions/8109/why-are-x-and-y...

There’s also a history of using ‘X’ as the designation for eXperimental planes, e.g the X-15.

I always assumed that was the inspiration for the use in tech branding like Google X - conjuring up images of skunkworks, etc.

hmm:

mac os: numeral

generation: variable

google: eXperimental!

malcom: variable

elon: hey yo, check it out i tried to register x.com and actually got it!

the question is... chitter or xitter?

Am I the only one thinking of that picture of ten roman legionaries, captioned "The X Men"?

For me, the 90's X-Men theme doesn't work in the movie 300.

ten fingers, ten toes, base ten arabic numbers

OS X at least has the excuse of having come out during the time when Generation X were the young adult audience sought after by marketers.

In contrast, today we have Gen X executives who are seemingly trying to recapture the glory days of the late '90s.