Nobody is forced to and neither should it be forced upon, but it will be desirable for most players depending on what they are doing. I always check out what's happening in system when passing through. I don't want to give up an opportunity.
Most players are going to do the least amount of work for the end result desired (usually materials, credits, or reputation to get ships). So if it's avoidable, it will be avoided. if it's an optional aspect of the game, it'll be made pointless by being able to avoid it, because the people who choose to not participate in legs, will cry and moan on this forum about how they're being discriminated against if certain things are achievable only thru legs.
So if Fdev does what they always do, and what has been the most damaging aspect of this game ....and make legs optional with everything available inside your ship as what would be outside it on your legs...then legs are pointless. It'll be an eye candy feature of no real importance.
Optional - separate but equal nonsense just forces each thing to be pointless/redundant to the game narrative and gameplay in general. All that ends up dictating what gets done is which requires the least amount of effort. Gameplay that exists in your mind and imagination is poor game design. That kind of mentality only really works to the game's benefit on single player games. But if you're all about the single player and that's what you wish this game was, then you're still being screwed by fdev's indecision by not having control over your game like you should in a single player game (mods).
Fdev needs to make planetary landing necessary to progress thu the game. They need to make legs necessary to progress thru the game. They need to make the environments necessary for players to interact with. The roles can vary in what you do within them, trader, combat, explorer, but they need to make the environments necessary to be in.
As for the comments I made regarding the BGS. None of the states, government types, controlling factions have mattered to me since the game was released. They might as well all be the same, it doesn't change anything I do in the game no matter what system I'm in. That's a huge failure. I should not be able to do that and it shouldn't matter what role I've decided to play as, none of those things should be something I can completely ignore in the game. Yet they are, and I have for years. The BGS is a weak sauce shadow of a player driven dynamic that goes out of it's way to not matter and the non-limited resource economy only helps make it more ignorable.