It's really not, lol. Soda in general is just awful on the GI tract, energy, mental health, diabetes prevention -- you name it, soda probably hurts it. Unless it's a bad thing. Then soda tends to help it.
I used to drink nothing but bean water and eat nothing but ramen. After narrowly avoiding kidney shutdown, dialysis, and possibly even death in my mid-30s, I started eating healthier (not as healthy as I should, but hey, baby steps) and switched to drinking almost nothing but water with the occasional tea.
It seems, though, that right now, at this very moment, my biggest issue is... sleep deprivation exacerbated by dozing/short naps that just don't do anything to catch me up on my need to slumber.
Well, in that case, bring on the caffeine. Bring on the tea. >ω<