The biggest problem, as alreayd mentioned, is that Nintendo actually had room for a price cut. For two reasons: 1) they have enormous financial reserves and zero debt, and 2) they priced the system well above production cost to begin with, so a price cut simply took a money earner in to a modest money loser. By contrast, Sony has 1) much lower financial reserves and over 8 Billion in secured debt, and 2) launched the Vita at a loss to begin with, so a significant price cut would take a money loser and turn it in to a massive money loser.
Sony left themselves very little wiggle room.