People who sell services generally don't want to fill in a quantity. It would be nice to have a default option to make all quantities in the product schedule 1
You can do this! It's very, very poorly documented. You have to call tech support and get them to turn this on. I forget what it's called, though.
kristinf
Aug 1
Jakester is correct, Support can enable this for you. Search for "Supply default opportunity line item values" in Help & Training and you'll find a solution that explains what happens when this is enabled. If that works for you, contact Support to have it enabled.