@22
I am not against study of pawn endings: you should study them just like you should study KBN vs. K despite it not occuring frequently.
Chess Fundamentals by Capablanca treats rook endings, minor piece endings, queen endings, pawn endings, and the 5 basic checkmates, all in 60 pages only.
So in his expert opinion all of it is fundamental.
@19
"rook endings are important too, but to play them well, you also have to be good in pawn endings." ++ You argue above that KBB vs. K (and also KBN vs. K or KNN vs. KP) do not occur that often and thus are worth less study. Pawn endings occur less often than rook endings.
Pawn endings occur *all the time* at the beginner and intermediate levels. In master games, they're less common, but only because (1) masters are better at judging when to avoid them and (2) most master games are drawn or resigned before they reach the pawn ending stage. Nevertheless, even in master-level rook endings (or knight endings or queen endings, etc), the *possibility* of pawn endings is contemplated repeatedly. They really are the foundation of all endgames. And they're extremely complicated, extremely unforgiving, and often counterintuitive, so they particularly repay careful study.