Why are HTs not so good for diffuse thinning?

[Stanth]

Hi,

I've been told a few times that HTs are not as effective on diffuse thinning areas... is this because you are likely to continue to lose the rest of the hair from the recipient area in the near future, so the new transplants will look thin, or is it because the transplant procedure can damage some of the existing hairs?

Wondering whether to go down the HT route and managing to find many reasons to stall on this.

Cheers

Stanth9