When you say "I don't want to complain, but..." we assume you're about to complain.
You love to complain. You love to make sure you are heard on the issue at hand. All of us, on some level, enjoy complaining. The hope is our complaints are on worthwhile things.
Let us no longer give the precursor of not wanting to complain when we cannot wait to complain.
When you say "I hate to say this, but..." we assume you love to say this.
Come on! Admit it! Whatever you follow up that precursor with is something you have either been dying to actually say at the right time or it is something you actually say all the time...BECAUSE you love to say it.
Save the theatric! Just own it. You cannot wait to say this out loud for everyone to hear, so just say it.
This phrase usually completed with: - "I told you so" - statements about the state of an organization or country - statements about a person to or behind their back