Hmm, I think the problem here is that we're falling into extremes here.
Sure, there are "math nazi's" out there who want to put in a ridiculous amount of rigor in high school courses, and sure, this is unnecessary. Seeing Dedekind cuts before analysis is rigorous, but it is certainly too much. (epsilon-delta's is something which can be given in high school however, it works in my country, so it could work everywhere).
However, the OP is the other extreme, I think. He is an "application nazi". That is, he just wants the people to be able to apply calculus, and not worry about the theory at all. This attitude is as bad as being a math nazi.
People who study calculus must
study mathematics how it really is. I don't want to focus on the theory, but at least we should give proofs and show that this is all logically grounded and can be made extremely rigorous (if we want so). Not presenting the theory involved is actually lying to the students.
Of course we should give applications. In fact, the main focus should be in applications. But theory and proofs are necessary. I don't want a student come out of calculus say that he took it all on faith. If that happens, then the education failed.
The same thing happens with everything really. If I take a physics course, then it should be made clear to me that everything we do is verified by experiments. Fine, we can give physics without even mentioning the word experiments. Just show the fundamental laws and make exercises. But that would be lying. When teaching physics, the teacher should show the student the main methodology of physics: experiments. And when teaching math, we should give the methodolody of math: proofs.
OK, engineers will find the proofs useless in their later carreer. But at least we should give them some sort of "general culture". So that they don't graduate without knowing what math is really about. An engineer who can't do proofs isn't a bad engineer, but I still think that in that case, the education failed to show the engineer what math is really about.
Teaching a subject shouldn't just be giving all the techniques necessary. It should also try to give a broad picture of the field. If I TA courses, I always try to do this. Students don't always appreciate it, but I wouldn't feel good if I just let them make mind-numbing calculations...
Also, I find the comparison between creationism and proofs of an extreme bad taste. I think it's quite sad if you can't see the difference between these two examples...