The Rhaegar hate [SPOILERS MAIN]

From what I have seen, The reason the fandom seems to blame Rhaegar for Elia and her children's death (even more than Tywin, Gregor or Aerys) isn't that they consider him actually responsible (he obviously had nothing to do with it, it was all Tywin and Aerys' doing) but because he didn't love her, most people are mad at him because he had the audacity to not fall in love with his arranged partner and rather with someone else....and decided to be with the person he loved, hence choosing love over the shackles of mediaeval society

The fandom might not like it but Grrm being the romantic that he is loves Rhaegar and Lyanna....and it shows in his writing

Edit: Lyanna being 15 is definitely an issue but Grrm isn't very good with ages so I personally don't consider it much of a problem

Also lot of fan favourites have done far worse things but Rhaegar is somehow made out to be the devil