Who really cares about the bottom? I don't care my country was 22nd or 18th or whatever.
It's almost impossible to create a system that will 100% fairly decide the results from first to last place. Desperate tries to invent such a thing will make the voting process weirder and less understandable for viewers and the contest is for viewers and not for jury-who sometimes even made up their rankings to have one
I do not agree on the first part. As shown, the range of shifted places is way bigger and it does make a difference to most viewers if their own country/favourite songs ends up in a comfortable midtable position or dead last with zero points. Especially if this happens year after year. Austr(al)ians would not say: "Alright, we rank 14 (13) positions lower than a country which has the same (an even lower) amount of points as (than) us subtracting diaspora grants. But that's all fine and dandy given that the difference in points is not really great and in case we have a competitive entry such things will not interfere anyhow." They would be more likely to get bitter and impugn the legitimacy of all results, as it already happened not so long ago. I'm shuffling the reactions of different groups (the broadcaster, the media and general people) swiftly together but you get the point. This year it was hard for them too complain because both saw themselves profoundly 'overrated' (in relation to actual popularity) by the jury but under a system which gives all power to viewers at home (which I think is desirable) it would (again) court a lot of resentment in the long run.
My idea is to widen the number of countries that receive points in each national vote. I still prefer a positive scheme to a complete ranking one. One could even keep the tradition of the 'douze' by adding 9 and 11, and start counting with half points. E.g. 15th = ½; 14th = 1; 13th = 1½; 12th = 2; 11th = 2½; 10th = 3; 9th = 4; ...; 4th = 9, 3rd = 10; 2nd = 11; 1st = 12. It would also be an overdue adjustment to the gone up attendance at the finals of the contest. Moreover you are right that jurors should not be forced to rank more entries than their panel can eventually translate into points.