Likewise, the license explicitly says that the software is provided for free, therefore it isn't valid to complain about people not paying for it.
Nobody's on the side of the big corps here, but "why aren't you paying for this thing that I've given to everyone explicitly for free" seems nonsensical.
I think both complaints are valid. Being legal and being beyond complaint are very different. "explicitly for free" is the legal contract, and it's okay to have norms that extend beyond that.
The point is, people apply legal logic to the payment and moral logic to breaking the code.
You can either agree that this guy is an asshole but these companies totally deserved it for leeching off his work, or you can say that they're both in their right according to the license.
But the argument that "he's an asshole because these companies had no obligation to pay him" is extremely dumb and hypocritical, and that's what many people are saying.
> THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
This makes it pretty clear: The author is NOT liable.