Within 90% of the games I play or see they end when one player decides the other player has some considerable amount of advantage over them and quit. Assuming this is true. I don't understand why decks that rely on building Nora advantage aren't top tier. For example, an IS/FS build which runs Nora mines, Marsh Song, etc. I have some theories but I'm interested if anyone else has insight.
Because by deploying these runes you are sacrificing short term advantage for long term. Which, if the opponent can take advantage of it, means that you are going to lose before they pay off.
badger is correct. playing things like nora mine or marsh song are a TEMPO HIT to the player using those cards. You are immediately weaker for 2-4 turns after playing them, before even begining to get any advantage from the rune played, not to mention the deck slot.