Actually I had offered "(not-so-)old school" isometric graphics , so no Unity etc involves. I think it is easier to achieve than going full 3D, AAAs set bar too high for decent 3D graphics.
Using 3D with a fixed isometric-view camera is supposedly easier than doing 2D isometric nowadays - though I don't have personal experience with that. If the camera is pulled back far enough
So, what I get is that it's less feasible especially if no natural leaning involves.
The idea I'm trying to point out is that making any game of decent quality takes work, and to get people to labor, the labor needs to be rewarding - either financially, or a requirement for survival, or personally satisfyingly enjoyable to work on. It's more personally rewarding to work on the projects you want to work on, then for you to work on projects that others want you to work on.
And for Lincity, it has more than lack of funds issue. considering average hardware today, a DirectX based isometric raster engine matching/mimicking capabilities of Simcity 4 shouldn't be that impossible imo.
It's not... but it lacks manpower working on it. Where is that man-power? Working on their own games. How can you get that manpower to work on Lincity instead? Pay them. With what? Opensource projects lack funding except for those that have commercial backing or immense fan backing.
If anyone wants a specific game made, they have two options: Do the work themselves, and recruit others once you can prove that you're doing most the heavy lifting (and before we open a can of worms: amatuer "game designer"/"idea person"/"project manager"/"leader" roles don't count), or fund the project.
If someone wants me [or any developer] to stop working on what I want to make, to instead make what they else want me to make, they better have some way of compensating me... otherwise, I'm going to work on the projects that interest me.
In every single project, opensource or not, there is always compensation. Either money, praise and attention and ego-stroking, friendship/community, authority/administrative power-trips, creative output opportunities, or something else.
And I don't really get why you think I am asking you to code me a game for my very own pleasure.
We're just using you (as someone wanting a certain type of game) for the sake of conversation. I don't view you as someone begging others to do the work, but just asking a good question and that we're trying to give a good explanation for.
To put it another way:
For any given person 'X', not everyone shares X's tastes in <type of media>. If 'X' wants more of <genre of media>, 'X' needs to either learn how to make <type of media> (like you currently are), or else use extrinsic motivators like money to get people who can make <type of media> to stop making the type they want, and instead make X's favored <genre of media>.
"I don't get why they neglect some genres almost on purpose."
There isn't enough manpower to go around for every game that should get created - there is more demand for skill than there is supply, in the game industry.
1) Developers first have to spend years learning how to make games.
2) Then they start making small games and work up (taking more time).
3) Then they work on the games that interest them.
4) But they only work on these kind of games when they have time, since they're usually working full time jobs and need to spend time with their families and friends.
5) As an indie, they are willing to work on games that don't directly interest them...
6) ...but there has to be a market for it, since they want to benefit from it.
7) ...and it has to be economically viable for them to create it with whatever limited budget they have.
Want an new innovative simulation game made by a small studio? Prison Architect is one. It's still in alpha but is available for purchase on Steam.