TechCrunch writes, Editor’s note: Adam Rifkin is co-founder and CEO of PandaWhale, an online network of interesting things and people. He has never owned Facebook or Zynga shares. . You can follow him @ifindkarma. Facebook and Zynga have experienced similar roller coaster-like devaluation from their peak stock valuations, and they’ve been partners for years, which is why MarkZ and MarkP often get lumped together in the same sentence by fearful investors whose stock is underwater: “Facebook and Zynga (insert analysis here).” Such bundling masks a deeper structural truth. The reasons...