Transactions today take less block space than when bitcoin started, because of some very clever cryptography tricks that are backwards compatible (think about older, slower USB devices and newer faster USB devices still working together and fitting in the same plug) with the original network. Increasing the amount of block space is a lazy way of trying to get more transactions; since it isn't backwards compatible it creates political strife because you are forcing people to upgrade, and that is dangerous to a network built on consent to a common set of rules.

Hopefully that makes sense.