Disgusting, repulsive, gross - all words I've heard people use to describe Vegemite. Of course, being the adventurous foodie I am, I don't take anyone's word for it and I MUST try it myself before passing any judgments. It's honestly not bad at all. It's incredibly salty and has really wonderful umami. I've actually grown to like it a lot. As with most strongly flavored condiments, where people go wrong is when they use too much of it! If you take a shot of soy sauce straight, of course it tastes awful! But a few dashes into a dish could add just the perfect amount of savory depth.
I have to say I didn't have the best first experience with Vegemite. I was on a boat on the Great Barrier Reef and the Aussie crew members were hazing Americans (as a lot of foreigners love to do for some reason) with Vegemite. They told me to take an M&M sized chunk of Vegemite straight. It was really salty, but I didn't find anything repulsive about it at all. Even Aussies don't like Vegemite when eaten in that manner. I learned later that the typical method of enjoying Vegemite is to spread a layer of butter on toast, then follow with an incredibly thin layer of Vegemite on top. It's really quite delicious! The initial flavor is salty, but it coaxes out a really nice sweetness out of the sourdough bread I spread it on. Follow with a good umami lip smack and that's exactly how I enjoy Vegemite!
I highly suggest you give Vegemite a chance before throwing it on your food blacklist. =)