I was thinking this.
Do open source projects devalue paid for programs? Yup. Why pay when some nice chaps make it for free for the love of it?
Does that mean all programs should be free? Nope, can't rely on altruism to cater for all your needs, and altruism should be a choice of the creators, not an requirement of the consumers.
Do the two models cause problems sitting side by side? Undoubtedly.
But, its just a reality you have to face I suppose.