For certain situations, Tradition is better, undoubtedly. But I think the overwhelming preference for it among players is because most players would prefer to play unmolested. In other words, OCC, cranking out all the buildings and wonders they want, making a settler when they finally decide they want to expand, no pressure, just building their city up. The bonuses from Tradition support that mindset very well.
The bonuses in Liberty are all about getting your cities up fast, your workers up fast, your archers up fast, your improvements up fast. Fast, fast, fast, aggressive play. Which just so happens to suit Domination well, and also Deity, because you can defend yourself better and get your cities out in the choice spots. (Which often triggers aggression)
Now, the consistent response I keep hearing is that settling cities that aggressively is a mistake, you don't need 4 choice city locations, etc. etc. but the reality, backed up by the comments in every challenge thread, is that often you get attacked even when you don't forward settle, and that two cities, or non-ideal spots, just don't have the growth, production or unique luxuries to keep you competitive.
Aggressively settling 4 strong cities and defending the DoWs if they come will often ensure you don't get Shaka'd or struggle to win your victory condition later.
Yes, if you can get 3 strong cities out with trade routes, you can win the game with Tradition or Liberty. But the difference between getting a good expo spot and not getting (On Deity!) it is almost *always* whether you settle before t45. Which is why when I play tradition I always start building settlers by roughly t30 or 4 pop. It's the only way to keep up with Liberty when it comes to getting 3 cities up. Which you eventually need. This only 2-city NC thing is great in a vacuum or on Immortal or below, but if you do 2-city NC, 2 is often all you'll get.
And, for getting 4 cities settled, Tradition can't compete. So, Liberty's (notable) nerfing in BNW doesn't change the fact that it's very effective on the higher difficulties. I'm not saying you can't warmonger with Tradition, or that you can't get 4 cities up with Tradition, but most of the tradition proponents are suggesting starting with 2 or 3 cities, in the long run, if you don't get more, will counteract the advantage of tradition's extra growth, and likely cause you to struggle to keep up with the AI in the long run.
Yes, if you do get your cities up quickly, Tradition outperforms liberty in the science game, especially IMHO because of the free, instant and early aqueducts. (IE before teching engineering if you have good culture) And civ is all about science for CV, SV and Diplo. But only for the long haul. For the early science game, Liberty is actually better. The early academy you can place makes a big difference. And the stronger infrastructure, and (likely) better placed cities, plus more production early for units, makes Deity more survivable.
But, it's not "next turn, select building, next turn, select research" for the first 100 turns, which, no offense intended to anyone, is what most civ players are most comfortable with. Most civ players have been playing primarily peacefully forever, and since they're not experienced at warfare, they're intimidated by and unfamiliar with how aggressive play can benefit you in a game that ultimately doesn't end in a domination victory. Just my two cents, having been that guy. For a long time, I was only attempting Domination on lower difficulty levels because I just wasn't that good at it. I liked OCC because it was less to think about. I liked SV because you didn't have to juggle warfare, tech, and build priorities all at once. Then I got bored of it, and that's when I started appreciating the benefits of Liberty. Up until then I was exclusively a Tradition player. For years!
And yes, I'm completely influenced by Deity play. But here's the thing, Deity play is different, admittedly, but in many ways it's the true test of an efficient strategy. Inefficient play can still lead to victory on lower difficulties, but on Deity, it starts to fall apart. Which is why I think you see way more Liberty on Deity than on lower levels. You can "get away" with things on lower difficulties (things FYI that would never work against an aggressive human opponent) that allow you to maximize the benefit of tradition... like building workers and buildings instead of troops. As soon as you start to need to defend yourself, (which you should always need to in a properly balanced game) Liberty starts to look a lot more appealing.
Also, I totally agree, Liberty should get the faith GEs... doesn't make sense that Tradition gets them. The free aqueducts is of comparable benefit to the free GP in Liberty. The faith GEs are just the gravy that makes Tradition better in the late game, and for a growth-focused tree, GEs are the balancing factor. IE you've focused on growth so don't have great production... boom GE to save the day. With Liberty, you focus on production, and then there's no growth to save the day...
