Agreed.
I also don't like other aspects of the rules, however, especially that Intelligence and Inventive Genius don't add directly to it. It would also probably be cooler to reward higher-magnitude spells, high Arts, and high auras. I once tried to come up with alternative rules for OR; I'm not sure how well that succeeded. I fear they only made OR easier 
Not every magus, certainly, but enough for things to start to get weird. You have an entire House (well, half a House) devoted to this kind of thing, after all. And other magi, from other Houses, will surely join the fray. Given the long Hermetic history, and the number of magus-years devoted to OR this entails, I think we should have lots of Discoveries. By these rules. Which raises all the troubles Heaven's Thunder Hammer raised.
Yair