Unlike tolstoy’s description of families, mergers and acquisitions that end happily do so for a variety of reasons. It’s the unhappy ones that are alike. This is particularly true of m&a deals done at the top of the business cycle, when hubris runs amok, lofty valuations make acquirers sloppy with their money and the most radical ideas are made to sound plausible. In this category sits Elon Musk’s shotgun wedding to Twitter, once again…