No dude, you are wrong. According to this (I am sure that there are other studies as well, just don't have time to look them up) study
https://www.ncbi.nlm.nih.gov/pubmed/7734029 the GH release is not lower for older people and I think that they would benefit even more than younger guys from using peptides.
The results were very similar when young adults and old adults used GHRP+GHRH. The GH release was higher though when both groups used only GHRH, I'm not surprised about this because GHRH only amplifies GH release when there is a pulse. Young people have a lot more pulses throughout the day so only GHRH works better on them. But there is no difference if you use GHRP+GHRH at the same time.