It is a very fickle industry and even companies with a decent reputation can change their attitudes when their managers are looking for a pay rise.
Is it sensible to rely heavily on Adwords? I myself will never put all my eggs in one basket anymore.
From what i know of the Adwords system, increasing minimum bids is not as significant for their bottom line as it is for OV's auction type system. So i dont really expect them to change that soon - there are so many other ways to maximise their return!
As the number of advertisers increase, the cost of technology to satisfy them increases also. It's only right that some of the cost of this is borne by the advertisers, otherwise we have a particularly bad service, non-existent account management and poor ROI.
In each industry minimum bids will rise according to the ability of a site to translate traffic into results. I know so many advertisers that have their bids grand-fathered at 5 cents but find themselves in 6th and 7th place with little or no traffic or results to show, whereas an increase to 10 or 11 cents will result in a much more prominent position and results to be proud of, it's just a false eceonomy in some instances to stay out of the game.