Apple has intelligent people making these decisions. So they know in their heart of hearts that the patents they hold are overly broad to the point of bogusness. They know that the majority of the tech market is also intelligent enough to come to this same realization. They have an awareness that lawsuits exercising these quasi-bogus patents will have a negative impact on Apple's public image. Therefore, the only logical reason for going through with the lawsuits is because they have concluded that the alternative -- letting Samsung + Google have their way in the mobile market -- would be far more damaging to Apple.
Apple's interests aside, is this good for society at large? Doubtful.