@Miroslav Glavic - I don't understand your thinking. You demand that a plugin developer is obligated to provide support for a plugin, which should be free, and as a result may possibly receive a donation from you if you feel they've earned it. By the way, I never said that a plugin that is commercial is automatically better than a free alternative. I don't think anyone has said this.
@Kevin Eklund - I don't know that 95% would agree, but many would anyway. It's becoming a hot topic as more and more plugin developers move on and abandon their plugins.

For what it's worth, most of the people who have given me donations never asked for support from me, and never contacted me in any way other than going to my Paypal donations page. Also, most of the people to whom I've given support have never given a donation. I can probably count on one or two hands the number of people who've donated after receiving support (which ranges anywhere from a couple minutes to send a quick email to hours of work, usually somewhere in between with a few emails or so back and forth), only one of which that I can think of which was over 10 dollars. Most that donated after receiving support gave $5 or less. All but one of the larger donations were from people who never asked for support.
Do the math: I get around 30ish support emails (and phone calls) a day for my free plugins. Statistically, most or none of these will give a donation, and if any do, it will be a few dollars. Being conservative, if I spend 20 minutes on each, and get $5 from each, would you consider that good compensation for the support time, not to mention for the development time?

Having said all that, let me be clear. I have no problems with with receiving little or nothing in the way of donations from most people for my contributions to the WordPress community, that's not why I do it. If I never got another donation I would still work on developing my plugins and love doing it. But please don't insult me and the other developers by having the telling us that we owe you support for the software that you didn't pay for in the first place.
MySQL is free. Go ahead and call Sun Microsystems and ask for support, let them know that you may provide a donation if you're happy with their support. Have you checked out Automattic's pricing for support?
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