The truth is they simply don't want customers without internet.
They want people buying digital games as they get all the money, vs. selling games for whatever price to retailers who sell them marked up to $60.
They want people paying for Xbox Live.
They want people buying/renting movies and shows.
And so on.
It sucks, but really why should they want business from someone with no internet, who primarily buys used games etc.? Hardware gets sold at a loss for a good chunk of a generation, so if someone isn't buying new games or digital content, what do they have to lose by telling that customer to go pound sand?
Just the nature of business. You want to attract the customers who will spend a ton of money with you, and not worry about those who spend little.
Now, this could well backfire as it's definitely pissing off the hardcore gamer crowd who buys a ton of games apiece. So i'm not in anyway defending them. Just saying we can't really expect them to really care about segments of the market with no internet, or the segment that primarily buys used as these are markets they don't get much money from anyway.