Yeah, the second passive was in ways more interesting than the first passive, but as for why they removed it? I'll try and explain...
The idea of the current one is since the initial Crit is 160%, it is supposed to go on a Crit build-- so for instance it can be a one item power spike into 3: stormrazor->zealitem->IE. Since the SR hasdecent stats on its own, and improves with more critical.
Alternately, it can be used as an item for a partial Crit build Stormrazor+zealitem. (No IE); those two items can be good in a burst build such as lethality. You can even go Stormrazor+zealitem+zealitem and forget about IE; your critical rate would be close enough to 100 there, accounting for the first hit always critting, which fits into many builds.
So going back to why there no special proc on additional Crits; is because of the 160% crit-- building additional critical helps Stormrazor become more powerful-- if it had the second passive; it would simply be a powerful crit item to build when you have high crit already, and frequently build after an IE+zeal+zeal build-- they wanted it to not be like the old Essence Reaver-- they didn't want it to be used to make an IE build stronger.
So 1. To be built with zeal before IE but not after IE. 2. To work with a zeal build without IE. 3. It's a lot about when items are built, most of the 8.11 marksmen changes are.