Some really hate the idea of a hypocrite. Like the Republican Senator Ensign who criticized Bill Clinton's "affair", and now has been exposed as an adulterer himself with a staff person.
I disagree in some respects.
I think it is good to aspire to do the right thing if you don't actually do it.
You are promoting the right ideals, and establishing a benchmark for the future.
This can be either for yourself, or for the younger generation.
The alternative is to quietly accept a lower standard of morality which then feeds on itself even more. A famous Senator once said we should be wary about "defining deviancy down".
By talking about the doing the right thing, and criticizing others when they fail, we are building a public square. Of course the best option is to live up to your professed standards, but second best is to be a hypocrite, rather than not having high standards at all.