Ethanol is a diuretic as well. And btw YOU'RE wrong, "tea" cannot be a diuretic. True "tea" is a plant, camellia sinensis, and a plant cannot be a diuretic. What you mean to say is that caffeine is a diuretic.
I didn't say anything about hydration, because that's not what makes a drink "healthy" or "good".
It's a fact that green tea is a very healthy drink and beer by comparison is not nearly as healthy.
Potential effects of tea on health
Sorry to further derail this thread folks, but honestly I cant believe I even have to explain this. Tea is better than beer in every way. period.