Tarq, it probably would be a good idea in principle!
That is basically true, however learning to fly a Cub will instill hands and feet coordination taking off and landing that will be more beneficial than learning on the 172....or have I got this all wrong?
I know it's always better to have additional skills etc, but I would argue that it isn't more beneficial (or marginally so) for someone who intends to do no more than fly a C172 on good weather days.
There are many many things in life which people could go to do and it would grant them extra skills that may be applicable in unique and uncommon situations, but you can't do everything so you do what is efficient and makes sense.