I think a big roadblock for 2-H crusaders is that they don't get the 30% damage reduction barbs and monks get. Any 2-H build would likely have to incorporate a more ranged / run-and-gun type play-style as a result.
As for 2-H in general, there are two main problems 1) their stats don't compare well to 1h/OH and 2) they are slow, and slow is no fun.
So I see everyone thinks you need a shield to be a crusader. I have to 100% disagree with this as my crusader (fire build) absolutely smashes through everything in T6 4 man party or solo or whatever. I got really annoyed that everyone says you need a shield and have to use set gear, well once again I disagree. I have put together a build that is fun, looks like a warrior from the pit of hell and proves you DO NOT NEED A SHIELD! The best part about Diablo 3 is being creative with your build. If I was not at work right now I would break down my build for everyone but it will have to wait, maybe tonight or tomorrow we shall see. Try a few different things out and I guarantee you can be creative with any build and not have to rely on set gear. This to me is the best part of Diablo. Good luck and have fun I will break it down soon.
Also... Sure you CAN play Crusader with no shield... But why on earth WOULD you? You're missing out ona LOAD of stats, plus depending on the shield they can have some fairly build defining Legendary Affix's (looking at you Jekangbord and Frydehr’s Wrath)
Feel free to link your build, I'm sure it's SUPER fun, but it'll never be as viable/effcient as a REAL crusader build, complete with shield.