I generally try to be charitable in assigning motives in life - there's all sorts of reasons errors are made, and more often than not, it's not maleficence, but either a simple lack of knowledge (not everyone has the same knowledge base or interests), misunderstanding, or simply slight carelessness. I know I've made my share of errors/boo-boos on a daily basis.
In this case, as I've always thought, f*** the Montreal engravers and their greasy, poutine-smeared fingers that tarnished the Cup.
I get that it's hard to get everything just right - this isn't Microsoft Word, where you just type letters and they automatically justify themselves. I'm sure there's a lot of advanced planning to do before engraving the Cup. You've got hundreds of characters to get on the Cup, and you also want to do it fast so that the Cup is ready for show...and in 1972, you didn't have the Internet, where you can automatically double-check the spelling of every name.
But there IS a dictionary, and common sense....how do they not know how to spell Boston? They even managed to turn "Deadmarsh" into "Deadmarch" as recently as 1996....two years after Yahoo came into existence. And this isn't a text message to your spouse saying that you'll be "picking up some pens at CVS" where an "i" gets accidentally inserted into a key word - this is the Stanley friggin Cup!
It's not the only error, either...
‘Bqstqn’ Bruins Among Brutal Stanley Cup Engraving Mistakes (Photos)
Apparently it's a family job, too...the Cup has had only four engravers, all who seem to be tied together. But...um...how do you keep a job with all those errors?
Hockey Hall of Fame - Stanley Cup Journals: 34
As for fixing it...eh. I sort of see it as a little bit charming, and a badge of hono(u)r that those Montrealers couldn't bear to write Boston on the Cup. Of course, their descendants would do it correctly in 2011, and that's what counts!