The "theft" spin on copyright violation is the result of years of lobbying by the media industry because they foresaw a drop in sales when people didn't need to buy the same thing over and over again.
If you don't own a Mac, you don't own macOS. If you own a Mac and some other computer(s), you own macOS for the Mac, but not for the computer(s). You might've purchased an upgrade to a newer version of macOS, but if you don't already own a Mac, you don't have something to upgrade, so the upgrade doesn't grant you ownership of macOS.
Now, from a legal point of view, it's a good deal different from (and more complicated than) that, but that's the basic idea. So don't make the mistake of thinking that because Apple gives macOS away for free to Mac owners, and don't use elaborate and onerous copy protection or license-tracking nonsense, that you're entitled to install it on something other than a Mac.
(or they just do it anyway and don't tell Tim.)
I don't think it's true since the phrase in question was present also in Mac OS X when we had to purchase each version. Apart from that, this part of the license is not valid in several European countries. When you think of it, it's quite reasonable: how could anyone dictate how you are using something you purchased? It makes no any sense.
Do you have a link maybe? My quick search found nothing...
That is not to say that numerous judges have not, on their own initiative, elected to grant holders many such powers. Judges can be just as confused as anyone, and more than some, and so exceed their statutory authority. Congress, moreso. But there is still a difference.
(Caveat: I’m not a lawyer, but I learned broadly the above from an IP lawyer.)
This still counts as “having control”.