In terms of eligibility, it is quite obvious that Barcelona deserves to be the champion in La Liga this season, but we also need to see that Real Madrid's chances of getting it have not disappeared at this time. Because we also don't know what will happen in the rest of this season to Barcelona so Real Madrid only needs to beat Barcelona when they meet again in a match in La Liga this season. Although Real Madrid still has to hope that Barcelona does not get full points when competing with other opponents.
I don't know what your reasons might be that Barcelona deserves it, this is a competition and anyone that wants to win will have to fight for it and this is something that is not given you show that you actually deserves it. And the three of them deserves it but they will have to prove there self because it is not about which club you are supporting.
And hope you are not forgetting that Madrid to want to win so as athletico Madrid do there us enough speculation on the three clubs on who is going to win, and if Barcelona eventually meets with real Madrid then the outcome of there game is always unknown to anyone because they don't seem to be stepping down for anyone. And since they are all focused and this always happens especially when the season is gradually coming to an end. And to some extent its now as if the season is longer, and the game have refused to finish and it is not that interesting.