I don't think either tastes 'bad' at all.... in fact, if you like meat and didn't know what it was my guess is you'd like it.... EXCEPT....

in the case of tripe it's not the taste I object too... others here posted recently how much they like it... which makes perfect sense to me... the taste is fine. It's the texture.

Haggis is 'normal'.... like you would expect meat to me... but tripe, to me, is more like a big gob of fat. Not quite that bad but closer to that than firm meat.