Yeah, the data is so integrated in to these phones that it would be VERY easy to accidentally use it. For instance, most droids use visual voicemail, so anytime someone leaves you a VM it will use data. As such, I don't believe the carriers will even activate a smart phone on your account without adding the data because they don't want you turning around after you've got a $500 phone bill and saying "well why would you guys even activate one of these phones without data since that's what they're designed for. if you would have told me how this stuff works, I would have just added the $30 so I didn't get stuck with this $500 bill". That's not to say that you would do that, but they've got to be careful from a liability standpoint.
I know you don't think you'll use any data, but you'd be surprised.
And why wouldn't you want data? What's the point of carrying one of these phones if you aren't going to use it? A droid without data is pointless. It's just a big ass phone you've got to haul around without receiving any of the benefits of having a smart phone.