I agree that tatemae is good for dealing with people on a day to day basis.

But for people who we have relationships with like girlfriends, wives, friends and workmates it makes it very difficult.

I have a few Japanese friends who really talk straight with me (I guess that is why I picked them as friends!!).

It seems to be a combination of how well they understand western culture and what sort of person they are as individuals.
Same as in any country, I guess, some people just can't seem to say what they really think
I am sure it must be frustrating for them because they will be unhappy about situations but not have the courage to say anything!