It doesn't make sense? No kidding, eh?

I think you've missed my point. You're claiming that people are losing shares because the block changes before they can find the next valid share. That is to say, at some point during the next block they come by a hash that would have yielded a share on a previous block, but is now useless. By this logic, you might as well be upset about all the hashes you zip by that would have given you a share on the next block as well.