They are doing, but what people want is different things, and what FD are adding might not be to everyone's taste - it can't be. If they add what OP wants there will be people complaining that its a waste of dev time. If they add something else, then other people will complain the devs are wasting time. Game development is a no-win scenario anyway.
And there is no hatred of the suggestion, dislike maybe, not want, for sure, would like devs to put their attention somewhere else, definitely, and of course, not wanting ED to become first person EvE, which unfortunately OP tends to provoke that reaction due to their choice of avatar and their long history of making suggestions to make it more like EvE. It wouldn't surprise me if more than a few saw who was making the suggestion and immediately dismissed it because of the poster - which is unfortunately, but people build up histories on forums that can jaundice people. I'm sure there are more than a few people around here who groan when they see one my posts
As I posted earlier, i'm more wondering what it would actually bring. It sounds cool on first glance as many ideas do, and i do think colonization definitely belongs in ED... but there needs to be something that you can get out of it... but not so that people will immediately go base building all over the place to reap rewards, then abandoning them. There needs to be a hook and a reason to then stay with the colonies... and i don't see that for the moment. Its not like FD are going to add like extra benefits to having colonized a system, not without giving the same things to existing stations, and if existing stations have those things, why coloinze.. except as i suggested, to set up a base a long way from the bubble.
Regardless, for me its something that could come later. I still want atmospheric worlds and other stuff before things like this, and fleet carriers, ie: mobile bases, might be a lot more interesting than more static bases.
Don't confuse those who are not interested in your idea or simply don't want as not wanting improvements. This is a fallacy people sometimes fall into. I think its fair to say we all want the game to evolve, just sometimes in different ways.