[csense]

> Why are people so interested in recreating a 'more open X'

To me, the biggest benefit is avoiding the problem of orphaned products.

Think about the problems caused by the shutoff of a major web service, for example, Google Reader. Reader users relied on a unique service provided by a company. When the company decided for whatever reason to discontinue the service, those users were left high and dry.

If you use a self-hostable version that runs on a commodity technology stack (i.e. the underlying OS/webserver/Redis/whatever layers are offered by many different providers and/or self-hostable), you can be pretty sure you'll be able to retire the service on your schedule, not the provider's.

If the product is open-source, this is even better because it makes the code more resistant to "bit-rot" (the tendency of code to stop working even though no changes are made, due to changes in lower layers.)