[Avshalom]

This is about cure versus treat. Google is trying to enter the spreadsheet market, not destroy it.

As an analogy Google Docs falls safely on the treatment side of the fence.

[yummyfajitas]

Google is trying to get 100% of the spreadsheet market with the goal of selling ads and maybe some corporate subscriptions.

If successful, they will destroy a vastly larger market (commercial spreadsheet software). Google would rather have 100% of a small pie than 0% of a big pie.

Similarly, Diabetes Cure, Inc would rather have 100% of the diabetes cure market than 0% of the insulin market, even if the latter market is bigger.