Dthrow to fsmash is so easy to avoid, it's not even funny. Your opponent can easily DI away Orchestra not airdodge into the ground. The fact that throw to can is hard to set-up isn't the problem, it's due to how unreliable the reward is. Most of the time, you'll just get a bit of damage. If you both go up to the upper blastline, it's a gamble since your opponent can kill you just as easily as you can kill him. It's not really worth since you can easily just do something else that has much more reward. None of these are reliable at all.
Uthrow -> Uair is decent though, even if you'll never kill with it unless your opponent is an idiot.