If people believe traditions are valuable, they should anticipate that searching the past for more traditions is valuable.

This implication is true, but the premise typically is not. The conservative defense of tradition-for-tradition's-sake isn't really a defense of all traditions, it's a defense of long-term-stable, surviving traditions. Don't think, "It's old; revere it." Think, "It's working; don't break it." For traditions which weren't working well enough to be culturally preserved with no searching necessary, this heuristic doesn't apply. To the contrary, if it turned out that there was no correlation between how long a tradition survives and how worthwhile it is, then there would be no point in giving a priori respect to any traditions.