Because this is an open forum where I can write what I want. You're a grumpy one aren't you?
To expand, I think Galbraith has a better long pass on him or is at least more willing than Garner to play that pass. He is also very nimble and operates better than Jimmy in tight spaces.
Garner, as intelligent as he is, can let his positioning expose his lack of athleticism. I've seen that more so in his brief outings with the first team.
Although Garner is very far from soft, Galbraith has a lot of tenacity to his game too but also seems to channel it pretty well which I think works in his favour.
As far as the intangibles, like I said it's hard to explain but the feeling I have with Garner is similar to that of Pearson, who many on here thought was a cert to breakthrough. No glaring flaws but I don't see him quite carrying his U18/U23 game to professional level in the same way.
Ultimately, all we can do is theorize. Garner could prove me wrong, ultimately I hope he does and I'm far from writing him off but that's my opinion.