And many of these same people probably (and rightfully) laughed at music and movie people casting piracy as “theft”.
It is irrelevant whether the thing or feature you took away is implemented in hardware or software. Notably it is often hardware functionality but the thief uses software to restrict it.
You could perhaps argue that another property crime might better describe it such as criminal mischief or in some cases fraud. But in any case it is a crime against someone else's property.
Is it theft if a company stops supporting TLS 1.0 clients that were previously supported?
What about upgrading service to only support a new form of authentication, breaking some clients?
What if the new authentication can only be done by locked down official client?
What if the company never advertised support through third party clients?
It’s wrong for sure, but I’m vicariously embarrassed for those who want to define everything they don’t like as “terrorism” or “theft” or whatever, strictly because it sounds so dramatic and casts the wrongdoers as not just wrong, but evil.
It’s old, it’s tired, it doesn’t convince anyone.
Simple “failure to adhere to terms of sale” is sufficient, and doesn’t have the baggage of being false.
It could be argued that it is not theft by various devious uses of legalise¹.
Personally I'd go with calling it, at best, deceptive sales practices (on the assumption that they knew they'd be moving this way long before they did), or possibly outright fraud if I'm in a less generous mood.
[FYI: Bambu A1 user for nearly two years, also have a Snapmaker U1, if I buy anything else it won't be Bambu unless their attitudes change. The A1/A1mini are still two of the best budget beginner printers IMO, though some clones come close, and I do recommend them if asked but with caveats around potential lock-in later and not believing promises due to a history of changed online posts, deliberately excluded from the WayBackMachine, and what to my understanding is an AGPL breach]
--------
[1] “There is a way to use the feature, so it isn't an attempt to permanently deprive”, or “you agreed to the possibility of such changes in the EULA”, and so on.