I remember getting personal developer support from Microsoft on CompuServe in the early '90s. MS engineers would actually send us some of their internal tools to investigate bugs. We helped them fix stuff in ODBC, and they gave us good support while we built what was, at the time, the biggest Visual C++ project they were aware of.
Obviously this kind of interaction is impractical today, but there must be some middle ground between it and what we currently see: companies shamefully abusing and hiding from their customers.