For us, we started German when my oldest was 5 (so 3 and 1 for the next two) - they all listened in. Not sure if we are getting too far...
My oldest 2 kids did a pre-school ASL course... but we didn't go anywhere with it after that. We are now doing it again as a family using Signing Time videos. It is hard to find age appropriate resources... but they are learning lots of words. So we started it with an 8yo, 6yo, 3yo and 18mo (and yes, the 18mo does sign... she signs more than she speaks at this point.)
But I agree, if you have no real reason for it except HS credits, I wouldn't put the effort and energy into it.
In our church, it is actually highly recommended to learn another language. My son will most likely go on a mission for 2 years, and it might be in another language. My daughters might also go on a mission. My problem is I wish they could learn LOTS of languages... and foreign languages have always been a struggle for me.
We are doing German because my dh lived in Germany for a time, and is fairly fluent
We are doing ASL because I took a lot of courses before, and it can be handy here.
I kind of would like to do French because we are in Canada and it is an official language, and is at times important to know for employment reasons (that said, I hated it after one specific teacher at school...)
and then there are a lot of spanish speaking people in our church... as well as it being useful in the States...
and then there are the benefits of Latin....
SIGH. Obviously we aren't going to do all of the above!