why isnt there a way to easily chat wth party members?

[Enkidoh]

Everybody knows about it, but the design of the game promotes an anti-social party system. So the result is everyone silently running dungeons and only speaking if they have to.

The reason for this is because combat is so fast paced, there simply isn't time to spend chatting about random stuff - unlike FFXI where combat was so slow you could easily get away with chatting while fighting. It's the price that had to be paid for having more faster combat (which players actually requested in 1.0 by the way - players wanted flashy, fast-paced battles like were shown in the original opening movie).