So 1-2 years?

Your "truth" is based on the assumption that everyone agrees that the gameplay sucks, wich is subjective, and that no one cares about more content as long as the core gameplay sucks, wich is also subjective.

While i see all the same issues as everyone else during every session, i disagree with your assumption. It's not perfect but it's functional and usually does what i expect it to do. I don't hear all that much hating from squad and corp mates either. There seems to be a number of players that find the current core gameplay at least acceptable.

And i'll even stronger disagree with the second part of your assumption. I can't wait for racial symmetry to finally be added. I want E-war, new maps, new competitive content, new NPE, new gamemodes and others more than a retweaking of controlls that i and countless others wouldn't even notice. This even ignores the fact that not working on content does not make them fix the core gameplay any quicker. We just won't have any new content.

Some studios had spent 12 years trying so and still failing.

There is more in 1.2 than just those mods that some players are going to like very much.

Tackling?

Can you link some quotes, most of their responses have been in the wrong topics lately.

I'm just anxious for 1.2. I would really like to get my hands on those new armor modules because at last armor tanking will be viable.

I would think:
maybe - some laser rifle changes to the sight
maybe - LAV "changes"
Memory leak fix
fix to vehicle recall
Drop uplink visible on radar fix
maybe - Timestamp in chat

The Dust Team is multi faceted what one team does the other team is not an expert on. So those responsible for physics controls and balance are not responsible for orchestrating the server being able to orchestrate an orbital artillery strike to smack a pesky destroyer out of the sky, is not responsible for allowing players to trade with each other, is not responsible on how the new suits look like.

There are teams and members constantly trying to keep the technical debt low but right now Dust 514 is missing a bit of everything from new player experience, to having enough types of guns, to have enough maps, to having enough game modes, to having enough reason to fight on maps. These are all missing and it does require many of the features on the roadmap.

Core will continue to be refined, making a good FPS at the core with all colors, models, and sounds removed is still something most people cannot do overnight and takes too much trial and error and some games which had gotten it right seem to have lost their way such as ID software.