I thought the same thing!  Then I started learning about FIX.  Unfortunately, it's a disaster.

Worst case of design-by-committee I've ever seen.  More of a trainwreck than all the XML standards rolled into one.

I think the meta-problem here is that FIX was created by the big Wall Street firms, and for them hiring ten programmers instead of one to implement some needlessly-overcomplicated protocol is no big deal.  In fact, the IT managers kinda like this because it increases the size of their fiefdom.  So, sadly, pre-bitcoin the organizations in a position to standardize this kind of thing also had an incentive to make it as complicated as possible.

In principle I'm in favor of standardization, but if an API is designed well it should really only take you 2-4 hours to write a plugin for it.  I guess that's part of the reason why I'm so prone to rant about crappy APIs.  If the exchange does a good job, the fact that there's no standard isn't really that much of a big deal.