My main issue with a lot of TNG was that the Federation became hypocritical. In TOS Kirk has a line when talking about the differences between the Federation and the Klingon Empire in TOS - "Friday's Child". In speaking the the leader of the Capellan Tribes Kirk states: "Your world is yours, and will remain yours.." and I always took that to mean: "The Federation will not tell you how to run your world, govern your people or tell you your culture is 'wrong'.
There were many examples too, of member worlds whose cultures WERE very different from Earth - and yet they were full Fedration member worlds. There was the people of the cloud city Stratos (TOS - "The Cloud Minders"). They used torture and had the death penalty, and whie Kirk and Co. didn't like that - again they conceded it was their world; and the ONLY reason Kirk interfered was to make sure they kept their obligation to another member world in crisis.
Contrast that with how TNG treats Worf and Klingon culture EVERYTIME he does something that's not Federation politicaly correct. The one I really recall (and really felt Picard was a ^%$#! hypocrite for - was when he dressed down Worf for following Klingon tradition in challenging and killing Duras for mursdering the mother of Worf's son - Ambassador Kehleyr. Hell, even the somewhat cowardly Duras AGREED TO THE DUEL because it WAS a valid claim under Klingon law and culture.
But yeah, as soon as Worf returns - he gets dressed down and lectured by Picard:
PICARD: Mister Worf, your service aboard the Enterprise has been exemplary. Until now.
^^^
(Of course this wasn't the first time Picard dressed down Worf for following Klingon heritage, but hey Picard's old.

)
WORF:
Sir, I have acted within the boundaries of Klingon law and tradition.
PICARD:
The High Council would seem to agree. They consider the matter closed. I don't. Mister Worf, the Enterprise crew currently includes representatives from thirteen planets.
They each have their individual beliefs and values and I respect them all. But they have all chosen to serve Star Fleet. If anyone cannot perform his or her duty because of the demands of their society, they should resign. Do you wish to resign?
^^^
(Yep - in the TNG era if your culture doesn't conform to the human culture of the Federation and you're not willing to subvert your personal beliefs, you can't be in Star Fleet? WTF?)
WORF: No, sir.
PICARD: I had hoped you would not throw away a promising career. I understand your loss, We all admired K'Ehleyr.
A reprimand will appear on your record...
^^^
(For what? Following Klingon law and Klingon cultural norms? <--- How enlightened/tolorant and 'non-interfereing the Federation is in the 24th century)
Picard (continued): Dismissed. Mister Worf, isn't it time for the truth about your father's innocence to be told? After all, you only accepted this dishonor to protect the name of Duras and hold the Empire together. Now that he has died in disgrace, what is gained by further silence?
WORF: Each member of the Klingon High Council has shared in that lie. They will not be so willing to admit their own dishonor. But the day will come when my brother and I will convince them to speak the truth.
^^^^
This was another issue I had with GR's retcon of the Federation for the 24th century. They went from being tolerant of any world's culture to - hey, the Human cultural norms of the Federation are the best and if you're an existing member world (or now want to join) you MUST conform...you will be assimilated...oh. wait....