Free WordPress Plugins are out there by the tens of thousands (as of this revision 54,855 46,773 at WordPress.org alone) and each one is made up of thousands to hundreds of thousands of lines of code. All those lines of code didn’t just come into being from thin air. Plugin authors pour a lot of themselves into the writing and testing of all that code before you ever had a chance to read about it.
My sense of fairness and balance demands that I get vocal with the users of plugins to compensate plugin authors for their efforts. Hold on, I know you’re thinking, “I’m not paying good money for something that’s free!” or “Why compensate anyone for all those useless plugins?”