While I can see how even my take is polarizing, looking at Difford's tasting notes of Fever Tree Refreshingly Light Ginger Ale, makes me think it could just be that. I make my ginger syrup using Jeffrey Morgenthaler's recipe of equal parts ginger, water and sugar by weight, resulting in a syrup which is balanced but still spicy. I would also suggest trying it with a ginger 'beer' as well. I feel like spicy ginger works well with the lemon to calm the sweet grenadine down. But one more warning, I'm only in my 20s, and I have a wet palate.
Ok so I just tried this again with the prescribed measurements, but I used an additional 2.5 ml Barr Hill honey syrup and subbed in Fever Tree Ginger Beer, the latter of which definitely now brings this into a flavor profile which reminds me of this thing when I had them as a wee lad. I also snuck in a dash of Peychaud's for color, but it fell far short of ruby red... This was by far the best ST I've had, but why is this a drink I feel compelled to keep messing with errr...
I think it's probably the only fabled non alcoholic drink out there, hence wanting to keep trying to find the right balance. When it comes to grenadine, either make it immediately after juicing your pomegranates, or just get Liber & Co. (since you're American). All the flavour, with a beautiful reddish-pink color.