More proof that too many manufactures and few privateer teams in F1 is a bad thing.

Bad performance is bad publicity and damaging to their business. That alone is probably enough for the team to pull out, but combined with the current economic client it was a near certainty.

How long before Renault goes the same way?

And I remember people people claiming BMW was one of the main big teams of F1 during the whole FIA/FOTA row, despite them only being on the grid for a few years, and their lack of commitment to F1.

Privateer teams like Williams will stay until the bitter end, F1 IS their business. The manufactures will leave in a few years if they don't see success.