Right, there has to be some! I've even met a few myself. But I'll bet the per capita is mighty low. ;-)
From my observation, there are (roughly) two types of people who love Vegemite, Marmite, Promite, etc.—those who like strong flavors like you and I do and those who are brought up on it from not long after they've been weaned.
If you check out the YouTube link in my other comment you'll note it's aimed at kids. For example, when I was in primary school kids (me included) would often have Vegemite and lettuce sandwiches (kids just wouldn't eat lettuce sandwiches alone). As contrast, our second sandwich would be something quite different (honey and peanut butter, ham and tomato, etc.).
I eat chilies, curries and such and was introduced to them very young too, so no doubt that helped. But not completely, some of my liking for strong flavors was innate. I recall when I was about 5 going on 6 my mother made me weak tea with lots of milk and sugar. One day I told her not to put sugar in my tea and only one week later told her to stop the milk and to make it stronger, ever since I've only ever drunk it sans milk and sugar (I simply won't drink tea if either is added).
You have definitely had the wrong matcha. Prepared the traditional way (powder, hot water, and a bamboo whisk), it is a bit foamy, strongly bitter, with grassy notes.
I generally like strong flavors (Matcha, fermented foods, heavy garlic, didn’t hate Durian) so it was a welcome find!