I'm not sure what you want to discuss; Rolling, self rescue or teaching. That said, I'll offer comments on all three.
Rolling, while I consider this a fundamental skill, it's not the first or second thing I teach or recommend learning. Rolling is the second line of defense of someone with solid skills in WW or the sea, the first line being a good brace.
Second, self rescue comes after failing to roll - if you have a roll in the first place - and in order to effect a self rescue or an assisted rescue you must first wet exit. Enough said.
Third, teaching. As an instructor myself, I'll point out that the wet exit is one of the first on the water skill that a beginner/novice is taught. This is not the automatic response of everyone, surprisingly. I've spent as long as 45 minutes teaching the wet exit to students to get them comfortable with concept of being upside down and having the presence of mind to execute this technique calmly and deliberately.
No roll is bomb proof, not to mention I've been bodily ripped out of my boat by waves a few times. We all swim, it's just a matter of time so we should all practice our rescues not only in the flat, but in the conditions in which we intend to paddle and are most likely to capsize in.