Anything you can get free will be pirated. You don't have to install the entire language pack; you can install just the Proofing Tools without the UI.
It is definitely wrong. You can get a lot of things for free and not "all of them" are pirated. MS sells us a software, a word processor in this case to process words. The software ALREADY includes spell check and proof reading. You only need a dictionary
and thesaurus for it. MS might have compiled a dictionary and thesaurus for every language (And I really don't think that they have done such a thing. For instance for Turkish, they use the official thesaurus of the state (which is actually unreliable among
many Turkish speakers and writers) and I never heard that MS paid any royalties to use it. So MS basically pirated its own thesaurus for Turkish language.
Using a thesaurus or dictionary while using MS Word is as I said, ALREADY included in the price. MS might try to sell us a thesaurus (which is presumably pirated by MS!!!) but in no way is anyone obliged to buy it. You can download any thesaurus from the
internet and if you find a way to use it with MS Word; it is nowhere near to piracy.
PS: You know that MS Word has also a CUSTOM.DIC right? You can just download a thesaurus for any language, copy and paste it in CUSTOM.DIC. Is this piracy? Of course not. But don't ask her, she will tell you that you have to pay if you want to print your
documents, pay more if you want to save them, pay more and more and more. Are you for real?