The Burrito License
Whether you wish to call it a licence or a contract is largely pointless- ultimately we have some sort of agreement between two parties.
Imagine there being a Burrito License that said that on any day you used the software you would be required to eat a burrito. You'd have an agreement and any day you did not eat a burrito you'd not be allowed to use the software.
That there was no signature does not invalidate the agreement. If you enter a pub with conditions of entry (dress, age, behaviour ...) then you don't sign anything or get the pub owner's signature. He can sell you a pint and immediately turf you out before you even drink the pint.
So if you enter into an agreement with MS you get to agree to the terms and conditions. If you really don't want to enter the agreement, then don't: take your computing needs elsewhere.
I dislike MS's methods as much as anyone, but dislike is not a valid reason to be irrational.