Well, it's terribly wasteful in terms of resources. And so, compared to just using plants where possible (like with alternative dairy, plant-based meats etc.):
1: it's not sustainable ecologically (compare: https://www.drawdown.org/solutions);
2: it wouldn't be sustainable economically if not for the subsidies
Well, that wasn't my main point and I did mean 10 weeks of gestation (just as an example).
Still, physiological responses are not the best indicator of mental states - plants and primitive animals (from sponges to bivalves) have them too, despite lacking the neurological development necessary for (or evolutionary need for) "consciousness".
In this case, the ability to experience positive and negative mental states, can be used in place of consciousness.
Especially the ability to experience suffering might offer reasonable basis for approaching ethical questions.
In terms of animal rights this is as simple as assuming that at least most vertebrae experience mental states, incl. suffering, from at least shortly after birth (which we can safely do)
In terms of abortion, this still leaves us with the additional question of weighing contrary interests of 2 individuals. This is trivial when weighing the interests of pregnant person vs sth like a 10-week fetus (obviously incapable of experiencing mental states) but maybe not sufficient for arguments about 30+ weeks fetuses, depending on personal values
I doubt it that the quality of life would drop significantly should the olives be harvested during the day rather than at night.
There are many problems to solve in the politics and economy which doesn't mean we cannot enforce specific policies for specific problems.
That's not how it works. The space being "clean" doesn't really help much. Consider the transport and killing, and also the fact that by far the largest number of animals killed for meat (excluding fish) are factory-farmed chickens and chicken factory-farming always looks the same