We have players that think both were bad, both were good, one was good and one wasn't (and within that, good and bad for different reasons). This isn't to say these demographics are equal in size, but they're all a part of the existing playerbase.
It's a difficult needle for the developers to thread.
Perhaps you are right about that. But that is exactly why the choice was available in the first place in Civ6.
You could choose to play the regular game where the Ages system was conservative and bland or you could have chosen to play the dramatic mode, where the game is perhaps more challenging.
The point is, the way to play was available for the player to choose. The C6 Ages system is Modular. You could live without it and the game would make sense.
The C7 Ages are very much so baked into the game, that it's quite tough to imagine what Civ7 would look like without it.
That's why many people say a classic mode is infeasible even though a classic mode is what people want.
I think it wasn't a bad idea for them to experiment.
I just think it was a bad idea for them to assume (maybe based on their own market research or something) that the way they designed the game is the way everybody plays.
And they went with a rather unpopular way to play, as it turns out (that's my opinion based on stats).
From the start they should have embraced a 'play it your way' type of game.
Like Smash, where you choose to play with or without items, on whatever stages with whoever you want. It would be quite unpopular for Nintendo to force you to play with Items. The same is true here.
I understand many mechanics are integral to how a game is played, and so you can't design a game where everything is optional.
So to be honest, they need to make sure that they only put in the base game what is certain to be their least divisive mechanics, and try to design something with broad appeal in the base mechanics, and work their way outwards from there.