It's just a matter of economics.
Some time ago the bowtie boys made the decision not to recall pickups because they estimated that the cost of settling the lawsuits would be less than the recall. What they failed to consider was that by covering up knowledge of the defect, they exposed themselves to hundreds of millions of dollars in punative damages.
FOMOCO was a little smarter, they either didn't have any test data indicating a propensity to explode, or successfully covered it up. Thankfully, that put an end to the Pinto, but didn't really hurt the company all that bad (Pinto sales were never that great). More recently, they were able to pass the buck on to Bridgestone-Firestone. It cost them a little in a few lawsuits, replacement rubber, and advertising, but Explorer sales are strong as ever.
Nissan, rebounding from serious financial trouble, can't really afford the negative press and potential class action lawsuit. Japanese companies have always been good at the "mia culp" campaign.