My understanding from conversations I've seen about Google Reader is that the problem with Google is that every few years they have a new wave of infrastructure, which necessitates upgrading a bunch of things about all of their products.
I guess that might be things like some new version of BigTable or whatever coming along, so you need to migrate everything from the previous versions.
If a product has an active team maintaining it they can handle the upgrade. If a product has no team assigned there's nobody to do that work.
My understanding from conversations I've seen about Google Reader is that the problem with Google is that every few years they have a new wave of infrastructure, which necessitates upgrading a bunch of things about all of their products.
I guess that might be things like some new version of BigTable or whatever coming along, so you need to migrate everything from the previous versions.
If a product has an active team maintaining it they can handle the upgrade. If a product has no team assigned there's nobody to do that work.