When they say they want a PhD, what they're really saying is that they want someone with a proven track record of generating and finishing their own researching projects, publishing top-tier papers, and who knows the state of the art in the field. Because you can't graduate from a PhD without that.

But if you happen to have those things without a PhD, then do apply anyway and I'm pretty sure they'll be interested.

If you don't have those things, then you may not be ready for these kinds of jobs.

There are several very successful academic and industrial CS researchers without PhDs - Simon Peyton Jones for example - so it can be done.