For drivers education, we are taught how to parallel park; part of the driving test requires it. However, not every city/town has parallel parking.
Another example is what to do when on ice. We're taught how to regain control of the car. However, most cars have antilocks that automate that. Some states don't even get ice.
If there was no such thing as a manual transmission car anymore, then I'd say 'yes' it does not need to be taught. But since they are still being made, although most people don't have them, it is another potentially useless skill that should be taught.
You never know when you might have to drive a 'Richard Gere' home...
I think that most people, before getting their license, should learn to drive a stick shift; or at least get the concept of the idea. Most cars are automatic nowadays, and it seems like Manual car drivers are dying off, in a way. Automatic cars are extremely easy to learn, while a stick shift is admittedly slightly harder; but not horribly bad. In my opinion, at least everyone should get the feeling of driving a Manual just to see how it feels before driving an automatic for the rest of your life. To suffer the "pain" while on a hill, and actually learning to be more cautious behind the wheel; as well as driving a Manual can give a fun feeling of having control.
Not any more than they should know how to hand-crank an engine to get it started. We have huge numbers of labor-saving devices, and to maintain that we should know how to do it "the old way" rarely has any true sense behind it.
In any case, one can learn after one gets one's licence, if need be.
Learning to drive manual, stick shift cars is a good skill to have, for example if you visit Europe (where manual cars are common) and rent a car there, however it's not necessary for people who just want to drive automatic. The automatic transmission serves as a good entry level car for the average driver and manual transmissions are there for those who want to go further. It's up to the driver to decide whether or not to go with auto or manual.
I don't feel like they should be forced, but given an option with benefits if they do decide to learn how to drive stick shift. Such as a insurance discount or anything else we feel would be a good incentive. Like we get when we going to driving school. So I like the idea just not forced.
As an off road driver, it was necessary to drive standard up until recently because the gear ratios in manual transmissions were better for steep hills. This is no longer the case. Many automatic 4x4s now feature 6, 7+ gears and have the same gear ratios as manual gear boxes. Quite frankly, there is no need to own a manual transmission truck any more. Since a regular driver can accomplish all of their potential driving tasks now with an automatic transmission, I fail to see why it should be a requirement for licensing.