Brave of you to run so far, and not consume the coffee within a safe distance of a toilet.
Maccha tastes like an old man's asshole, and no it's not stale, it wasn't made wrong. It just tastes like ass
It's interesting that you should have such expertise in the flavour profiles of the assholes of elderly men...
You haven't had maccha then or have had some fake maccha or really old and / or bad quality matcha
Maccha has a earthy and strong tea leaf like taste that comes in after the earthy taste
Could it be possible all the places you are going to prepare it horribly which is a low chance but not zero
Also there could be a chance that all the places you went too have a bad supplier
Try this recipe with good quality maccha and see how it tastes
It's possible you're just not used to the earthy flavour yet
I've heard this from so many people. I just don't like it. Why is that so hard to accept?