I agree up to a point, in that I would actually prefer it if it wasn't possible to build a gb before its age. Saying that players who do that are acting contrary to the "design" of the game is silly though; that ship sailed long ago. I suspect that the game designers never imagined that strategy would become as common as it in fact is, but clearly they knew that building age-inappropriate gbs was possible and they were ok with that. It would've been simple to design the game so it wasn't possible.
I don't understand why people continue to hang on to this fallacy. Why do people see building GB and/or acquiring out of age resources as contrary to the game? It's a fundamental part of the game.
In FoE, you build a city that starts out with Stone Age technology. Through research of new technologies you are able to progress your city through the ages. Your city exists in a universe of other cities, just like yours, researching their way from Stone Age tech all the way to Virtual Future tech.
You can interact with these other cities when they are members of 3 distinct groups. You can donate to each other's GBs, you can trade with each other in the market, you can aid each other, you can attack and plunder if neighbors, you can visit taverns if friends.
Your neighborhood, about 70-75 cities, is comprised of other cities at your same level of technical research and progression, primarily those in your same age. You have no control over who shows up in your neighborhood which is reshuffled bi-weekly.
Your Guild, up to 80 cities, which depending on the composition of the guild, can have cities at any level of technical research and progression, and from any age. You get the cities with the guild you join, which change as members leave or join your guild, or you change guilds.
Your Friends, up to 140, like your guild, can have cities at any level of technical research and progression, and be from any age. It all depends on who you invite and who you accept friend requests from. These cities will change as you add and remove friends from your list.
All the Tech Tree Controls is the tech you can be self-sufficient in. We can donate to GBs in other cities in other ages, we have access to those Blueprints early. We can trade in the market with other cities in other ages, we have access to the goods we need to build them.
You have to deny there are other cities, other cities with other tech, or that we can trade with other cities with other tech to think it's a violation of the game. Not to mention you can get any of that with diamonds anyway.
It's not very different than what Nation States do today. If you're a developing nation, you don't discover oil, then invent what you need to extract, refine, and use oil. You discover oil then import all the technology you need to exploit it. Which yes, sometimes gives us cities with grass huts built next to oil refineries.