Smokescreen of unanswered questions hides the biggest ones

SPOILERS abound, obviously.

Two braniacs here, who love mysteries, don't like answers spoon-fed, who watched with rapt attention, didn't do anything distracting while watching, paused frequently to discuss matters and who spent at least 2 hours after the final episode to try and get at least some of the loose ends tied up.

There are far too many open questions -- even more than other users here in other threads mentioned; every time we discuss an episode, we remember more unsolved mysteries.

However, we assume we reached the correct conclusion: that (almost) all people in Kettering are clones (e.g. those with rashes), that these clones are not perfect and reach a point when they need to be recloned (e.g. all the people bitten by their dogs = fresh clone versions), even to the point of having something like a "homing beacon" (=> Anna needing to go back to Tasmania without knowing why). The cloning, we are to assume, is done by aliens. Has, in fact, been done by aliens in other parts of the world (Norway, Alaska, Russia) over (at least) the past half century. Though, each time in very remote places and each time with the result that (almost) all people/clones stay in those remote places. This cloning happens as a reaction to humans messing up the world/the environment.

So, looking beyond the smokescreen of too many things left unexplained, we're left with one overarching, glaring question: to what end did those people get cloned? They didn't do anything to alleviate the horrible crimes mankind commits with regards to the environment; on the contrary. If you're extreme, you can see fishers and loggers as leeches, taking from the seas and the forests without ever contributing to restore the balance of those habitats. They were upset about the mill closing, but once they would have chopped down all the trees, they'd be out of work anyway. Same goes for fishers and oyster catchers.

If aliens realized humans were destroying the world, why not just get rid of humans? And if you decide to clone any, why not only those that don't contribute to destroying the planet?