I agree, with some addendums.
Okay, let's say Card Deck ABC has thirty cards in it. And let's say Interesting Rune Set XYZ has thirty stones in it. Both these sets are from fairly old traditions, and you can easily match up the thirty runes with the thirty cards without reaching or changing the meanings. They seem to mesh. This is something I don't have an issue with, even if the cards and runes are from vastly different cultures or worldviews -- there is Something Deeper going on here if they line up without effort, and combining them inflicts no indignity on either system, if done without rudeness.
But when different systems are mashed together uncomfortably, with seemingly little reason? No. It bothers me. It's like someone threw a party and invited people who don't speak the same language and don't have anything in common -- and if they did, they can't communicate anyway, so it's just a mess. Mashing different systems into tarot seems to say to me, "This deck isn't special or well-thought out enough on its own, so we barfed some unrelated yet popular system onto it so that you might feel it was worth your money." Sure, a lot of thought might have gone into combining those two unrelated systems, but what's the point? Adding an extra degree of unnecessary complexity, in my opinion. The majors have I Ching hexagrams on them, so it's a Serious Study Deck, right?
This isn't to say that the decks which do this can't be well-loved and used very well. Zan_Chan's study of the Haindl a while back proved that much. But I feel that combining systems, unless they mesh in a smooth and uncanny way, is undignified and messy. If I want to read runes, I'm going to darn well read runes! Not tarot cards with runes on them.
I think it's the reverse of cat-vaccuuming, as a metaphor -- cat-vaccuuming is wasting time, but this is more like dressing up a cat. It's pointless, potentially hurtful, and makes everyone involved look a little silly.