Pitching: left hand is better because it's easier to tag people out on first base.
Basketball ambidextrous is a huge advantage. They'll be unstoppable driving up and down the court. If a player can only dribble with one hand, it's easy to know which way they'll go when being pressed.
Same with soccer. If you're on the left side of the field, you need to know how to use your left foot to attack the goal as well as your right when on the right side.
If you can use both hands you will be more flexible. Note-taking will be easier. Most importantly you will exercise both of your hemispheres. Some parents try to make their left-handed kids completely right-handed? Why? Two is better than one. Likewise a right-handed child will benefit from training in the use of his less-prefered hand.
It is too much for a parent to force an unnecessary skill on his child. While it does increase brain function, it is not worth the risk of alienating a child because he or she does not see the point in learning a skill that then causes the parent to be strict in order for them to learn it. If the child develops a genuine interests in acquiring that skill, then he should pursue it. That's a better opportunity for the child and parent to actually connect.
I hardly think this is a pressing public issue. I think parents should worry about teaching their kids the basics at this point in our society. Being ambidextrous is not a particularly important quality that one can put on their resume'. Therefore, parents, just worry about something much more crucial to their well being.
Teaching your children to be ambidextrous is insane. Who comes up with these topics?
Unless you are born ambidextrous, you brain is either right or left wired. Trying to change that just causes problems.
Teaching your child to speak multiple languages is great; but, to use both hands, will hurt the child.
Ambidextrous Children Have Greater Risk of Language, Behavior Problems
Teaching kids to be ambidextrous is not a good idea because it just isn't worth it. We have lived fine using one dominant hand; why waste time teaching a skill that is useless? Instead, use that time and energy to teach children something useful, such as a new math technique, or how to tie your shoes.