There is theory, and there is practice. When in doubt, always err towards practice.
In the realm of role-playing games, the theory is that the medium is one wherein you can whole subsume oneself into a secondary environment ala Virtual Reality and live a secondary life therein, with an aim towards secondary life experiences that one cannot otherwise attain. The practice is that role-playing games are focused around a specific range of such experiences, build around a core experience, because RPGs are commercial products and commercial products exist solely to produce profit by satisfying demand- and the demand is far more narrowly focused than the theory would expect.
The reason for this is simple: role-playing games are games, first and foremost. It is the fact that it is a game that justifies the medium's existence, not the theory of immersive secondary life-experience. Gamers want specific things out of games, and RPGs that don't deliver get dumped for those that do. That's as true for the products as it is for the users, and it is this one fact that takes settings that have far more than what it's known for and depreciate those elements in favor of the core experience.
This is why BattleTech, despite it being as intrigue-filled as Dune, it's harder than herding cats to actually make a campaign not focus on Big Men in Big Robots stomping about doing Big Damage. The reason is that the property's core experience is built around just that. Even the tanks, fighters, etc. are secondary to that core experience. Politics? Economics? Remember how that went over with the Star Wars prequels? Yeah, like that.
(n.b.: You run into this problem with any RPG derived from a vehicle-focused action-adventure property, such as Palladium's Robotech and R. Talsorian's Mekton Zeta.)
This is why the viable settings are those that focus upon that core experience, and successful development thereafter likewise focuses on that experience. The other elements, where they are acknowledged at all, are so only to the degree that it supports the core experience and gives verisimilitude to those experiences. Franchises that don't want to do this branch into other media where that otherwise-extraneous information becomes commercially viable, and these days this is a deliberate practice for the purpose of making a transmedia intellectual property franchise. (e.g. Star Wars)
Gamers want specific experiences from specific media, specific genres, and even specific games which is why this RPG is known for one model of gameplay and that RPG is known for another. For the MechWarrior/A Time of War folks, they want to be that BattleMech pilot first and foremost and that's why stuff that takes you away from the cockpit tends to get depreciated in practice no matter now much in theory it should be really in demand. It's a matter of practical psychology, and the sooner you adapt to it and make it work for you the more satisfied your gaming life will become.