A few points here:
-- You should be glad that you got ANY warranty. I was not offered (by Verizon or otherwise) an AppleCare (AC) or AppleCare Plus (AC+) warranty when I bought my phone. I had to do research and decide on my own what route to take.
-- My brief research on the matter shows the AppleCare warranty having been discontinued 3/16/12 (when the new iPad was released) and I don't recall the regular AC warranty being an option when I got one for my iPhone 4S back around December 2011 so it's possible that the AC warranty was discontinued even back then. Further, when I called to inquire, I used the general term "AppleCare" and was not told about two different plans (and was sold an AC+ for $99) so I wonder if they had already done away with the regular AC plan by then.
Regardless, it begs the question of how a three-week-old iphone 4 would even be eligible for a standard "AppleCare" warranty and not the AC+ warranty. (not to mention the obvious question of how/where/why you ended up with a new iPhone 4 at this point in time with the 4S out and the new one around the corner). I would inquire as to how your iPhone 4 has a standard "AppleCare" plan when it was purchased after the end of AppleCare.
-- As others have said, go to a different store. You'll find a Genius sympathetic to your cause who will swap it out for you. My wife's friend from grad school is a Genius at a retail store and he's confirmed with me that replacements are (to an extent) at their discretion. Also, another friend of mine dropped and cracked his brand new 3G (or 3GS whatever it was) the week he got it. He camped out and everything and was so bummed when he cracked it. They replaced it free of charge. Point is the right person may help you. Have a good attitude about it (the opposite of your post above).
-- Similar to the point above, offer to buy an applecare+ warranty on the spot and pay the $50 replacement fee. Ask that of the Genius and/or the manager. Sure it'll cost you $150 ($99 for the AC+ and $49 "accidental damage fee") but you were intending to buy the warranty anyway, right?
-- I can't speak for everyone, everywhere but I've left my phone in the bathroom while I showered and never had a problem with it tripping the sensors.
-- I don't think it's Apple's falut that you didn't buy a warranty for your phone. As a paying customer who holds an AppleCare+ warranty for our devices (iPhone 4s and latest iPad) it's hard to have a lot of sympathy. When you bought the phone, you knew you were holding a (minimum) ~$500 piece of glass. You need to consider this viewpoint as well.