Re-using ball joints?

I've sold numerous brake and suspension parts on this forum, throughout the years, without anyone ever getting back to me, with complaints in reusing upper control arms, that have nice and tight, good ball joints still installed in them.
What problem is there in using something that probably has a few thousand miles to them, that were replaced, before the vehicle got smashed, and turned up in a Pick-N-Pull wrecking yard.
You put used engines, and transmissions, and drive shafts, with the old universal joints still in them, so whats the difference if you put an excellent control arm back in service with, ball joints in them that are in good condition.
Some of you guys out there, make mountains out of mole hills.
You aren't building the space shuttle, or the Martain rover.

Like Jim, I would also reuse good ball joints. I have some around here that I kept just for that reason. They are very tight, will get fresh grease, and should be good for a lot of miles.

I see no issue with reusing your old ball joints. Too replace them just because is a waste of money,time and effort. If you took your car to a garage for an inspection and they suggested replacement of the ball joints for peace of mind(even when they are still good) you would call that up selling and dishonest. If you choose to replace that is your decision. However in spec or out its one of the two.
some good points made here - but someone needs to answer the OP's question - How can I inspect my ball joints to see if they are re usable?