So it's obviously a bad move for Microsoft to offer "unlimited" storage with Office 365 and then take it away - especially how it was handled. They've create PR problems, a loss of trust, etc. I get that and it could have and should have been done a lot better.
But...the numbers they gave are interesting. They specifically said 75TB, over 14,000 times the average. That means the average is about 5.35GB per user if my math is right. So now, they're basically giving away (i.e., free) a little less than what is used by the average user (5GB). And their 1TB of storage with an Office 365 subscription is actually cheaper than what Google Drive (and DropBox and Apple) charges for 1TB ($120), plus you get Office. Not really a bad deal. You can get unlimited on Amazon for less, but for my $, I'd rather go with MS. Others may disagree. Ultimately, though, from a business point of view, what MS did actually makes sense.
Of course, from a trust & consumer relations point of view, it's a bad, bad move.
Out of curiosity, who has more than 1TB of files? I personally am at 800GB but I have all the source videos from my church's services going back to September of last year which I've kept simply because I could. I realistically need about the last three months. So it'll be a long, long time before I hit 1TB.