All plugin and theme authors shouldn't go on the whole "you getting something for free, my hard labour of love, bla bla bla bla bla, be quiet" type mentality.

After all, all plugin and theme authors, are making a living out of free labour of love, WORDPRESS ITSELF.

Yes we are entitled to complain about free plugins/themes. Unethical practices from some authors for example.

Unethical practices is violating my admin with: (1) "hey subscribe to my newsletter" (2) "Hey, I know you just downloaded and activated my plugin and had no chance to test it out, I still want you to rate it" (3) "Here are my other plugins" (4) "Go buy my pro plugin" (5) "give me free statistics" (think freemius). Things like that.

Now, I have done the following: (1) Bought many plugins/themes authors a ticket to a WordCamp. Some I included accommodation for the weekend and your flight/train/bus ticket to the WordCamp if they are out of Province/State.

(2) Interviewed author for a podcast I was co-hosting

(3) I will start writing a post about each plugin I use on my sites.

How many of these authors have THANKED WordPress, without WordPress, there wouldn't be their plugins/themes.

Yes it is completely wrong to purchase a plugin to just monetize it or complete change it around.