It depends on many factors if it's a disadavantage to launch late but this time for Sony it was clearly a disadvantage. Don't you think the picture would be much different if instead of Sony, Ms would have launched a year late ? And Sony knows that too - their orginal plan was to launch early 2006, a few months after Ms. And it's not an accident that Nintendo launched at the exact same time as Sony.
You say Sony was disadvantaged with way too much certainty for me, what if Sony had launched with MS and incurred similar hardware issues? What would that have done to Sony as a company? Would it have helped Blu Ray? Perhaps but what would a billion dollar loss due to fixing faulty hardware done to the company? There are variety of factors that go into a launch and I hope that anyone can see from the data I provided that launch dates really don't correlate with the installed based. And even installed base is the wrong thing to measure, what we should really be looking at is profit for each respective company for these periods of time.
With that said the difference between 2nd and 3rd place this generation is ~3M world wide so I think some of you are clearly overstating the difference in installed base between Sony and MS and the factors involved with how this generation has progressed so far. Further given Sony's interest in promoting Blu Ray, the issues with software development on PS3 and the cost of the technology I am not convinced they should have launched earlier than they did. MS clearly was able to gain market share in the short run without competition from Sony and Nintendo but again longer term it hasn't affected the installed base as much as some wish to imply. And when you factor the hardware reliability issues into it, launching first created some issues for MS too which should be factored into the evaluating the decision. Simply saying Sony wants to launch first or earlier than MS doesn't really add anything of value or accuracy to the conversation - as you can clearly see launching first doesn't guarantee success. You are entitled to feel that way but it is purely speculation.
The bottom line is that at the end of the day these companies are charged with generating profits for investors and superficial analysis that concludes first = x is wrong headed and I am certain that the big 3 don't view it that way. We do a lot of armchair quarterbacking which is fine but if we are going to speculate about a trend it makes sense to me to look a little deeper than one generation which isn't even finished yet to conclude how smart one company is and how dumb the other was.