> Yes, but what makes us believe they won't go the same faith as all the others?

Switching to an open source model would mean that only 1% of the users would pay anything. To make that viable you need a good business model for a much larger or a different market. The business model is vastly different with a vastly different product.

Just open sourcing the thing is an easy way to kill an existing company, which now has a small, but paying customer base.