That's no more valid than: At the beginning of your turn, determine how many standard, move, minor, and free actions you have. If you are dazed, you have one action (standard, move, OR minor) plus free actions. Unless explicitly stated otherwise, nothing changes this.
Your "consistent" approach is actually a retcon and creates a paradox. If I take a minor action and then become dazed, I can't do anything else? But, if I take all three actions and then become dazed, the universe doesn't blow up? How's that consistent? Instead, apply the daze going forward (not backward, i.e. no retcon) from the point at which it was initiated. You still can't violate the laws of the universe in terms of actions per round, but if you took a minor action and then became dazed, you would still get one more action (plus free actions). If you took a standard action and then became dazed, your one more action could only be a minor or move action (plus free actions).
This is exactly how our group plays this. Our group has had quite a bit of discussion on how this is supposed to work. Ultimately, we felt that since slow is explicit and none of the other conditions are, we felt it must be different. Just as I2K points out, retroactively looking at what was done just seems more bizarre than applying the condition from that point onward.