I think peaceful Liberty is underrated due to people typically misplaying it. The things that are fundamentally most important are the same whether you take Tradition or Liberty -- of course Liberty is going to look bad if you think opening Liberty means that growing cities is any less important.
In my opinion, the number of cities that you want to build is the same whether you're Liberty or Tradition, and you still want to grow these cities as big as possible either way. The difference is really timing. Liberty can typically get one more city than Tradition pre-National College, while Tradition is often better served delaying more of its expos until after the National College.
Liberty and Tradition both have their strengths and weaknesses, but your evaluations of these trees aren't going to be right if you think of it in terms of "going tall" or "going wide". With both trees, the goal is to "go big".
I respectfully disagree. People are playing liberty wrong because they think they need to grow the cities as fast as possible. First of all I want to say that liberty is not synonymous with wide, while tradition is not synonymous with tall. Although liberty is best played wide and tradition best played tall.
Liberty-wide get their total population from higher number of cities. Tradition-tall get their total population from higher average pop per city. The total pop is ultimately limited by happiness. You invest more happiness in number of cities for liberty-wide than tradition-tall. But you also presumably get more happiness by owning more luxes and local happiness buildings in a liberty-wide game. So the per city science penalty for a liberty game is offset by the higher possible total population.
NC for a liberty-wide game can be delayed and less crucial than a tradition-tall game. The bonus of NC is magnified by population in a single city. But in a liberty-wide game, not a single city will have a lot of pop until mid-late game. Aqueducts are unnecessary for most cities until mid-late game and early growth can actually ruin a wide strategy.