Does anyone else question the mythical man month? If I accept the basic assumption of the mythical man month then I also have to accept that NYC is a myth - there is no way that a city that size can possibly function. Lets start out with ten people in NYC and they add ten more people .... My own belief is the MMM is an apologists view of how we currently collaborate to develop software and products.
What do you question about it? The point of the specific essay was that the work of development/engineering cannot be sped up linearly by adding people. You still see this attitude with managers today: The team of 5 is running behind, let's put that other team on the same project, now it's 10 people. But those 5 new people:
1. Don't know the code base or problem domain. So they'll spend months getting up to speed.
2. Will increase the communication overhead (now each person has to coordinate with up to 9 others, not just 4).
On the small scale of this example, you may see good results. 5 more people isn't a huge amount of communication overhead, and if they're experienced (perhaps even formerly worked on the same or similar project) then you'll see an immediate drop in productivity and then a quick rise back to the new baseline. But will that hold with another 10 people? 20 more beyond that? Each doubling will not continue to halve the time to develop the project, there are limits, and at some point the returns will be negative. The additional people will slow it down. Not just the initial slow-down, but also the new baseline after things settle will be lower than before adding them.
For me the main point in MMM was that big things take time and putting more people to work on the project does not always speed it up. The communication overhead grows exponentially as amount of people increases while the productivity only grows linearly.
Large organizations function very poorly in a lot of respects. They're also the only way to get a lot of things done. In a lot of ways, it is often a bit surprising to me that large companies can coordinate activities to come out with useful outputs. On the other hand, there are clearly inefficiencies that don't exist with a 10-person startup.