Is there a valid reason to not write a letter of recommendation for a Soldier who has done nothing wrong and has performed well?

It's a letter of recommendation, he is not being recommended. If it wasn't voluntary it would be a statement of service.

Of course. There are many valid reasons, unique to each situation. I have friends since I was 5 that I’d lay down in traffic for. They haven’t done any thing wrong. That said, there are some things I’d recommend some of them for, and other things I’d never recommend any of them for.

On a previous deployment, I had a soldier who repeatedly volunteered for tactical opportunities. I loved the kid. But he was a ‘shouldn’t leave the wire’ type. Not to get too deep into him particularly, but he did nothing wrong, he usually did everything right...he was just better suited as an analyst, and only an analyst.

There’s nothing wrong with not wanting to write a recommendation, even for someone who does things right. However, by not doing so, I think the person refusing owes the soldier a straight, honest answer. ‘Not in the unit long enough’ seems like a cop out.

Best of luck

Could be they don't want to write it or don't know how to write it.....or both. Sounds like a possible "polite" cop-out