> Why was it OK for Google to incorporate their words into a for-profit search index which has increasingly sucked all the profit out of the system?

It wasn't okay, it's just that the reasons it wasn't okay didn't become apparent until later.

> The same people seem to have no problem with Facebook using their words for all things Facebook uses them for, however.

Many of those people will likely have a problem with it later, for reasons that are happening now but that they won't become fully aware of until later.