1.) Do we have any official stats on how many people use them or not? Most people I know (professionally, and personally) use the drives on occasion. for things like software installs, sharing data, importing digital movies that come on disks, etc.. etc.. etc.. The day will come when no drive is necessary, but we are still in a transitional time. Disks are cheap, and quick they don't use up bandwidth so they still very much have uses for many people. You may not use them at all any more, and that's great but many people do still.
2.) I'm not saying the price would or should go up, if they are so cheap to buy and Apple didn't lower the price on the computer by not including them then the drives should just be included (externally) since at that point Apple is no longer paying the cost of the internal drive. So unless you know that Apple will drop the price by not including the drive, then I'd say it's fair to think that the external drive should be included.