> If a dev releases his work free-as-in-libre and/or free-as-in-beer, they don't get to complain if the donations are "insufficient".

Of course they get to complain. Complaining and doing nothing to change the situation is what's problematic.

Doing work without reward, even if you did not expect any in the first place, can be soul-sucking, and it is totally normal to complain about it.

You don't do FOSS for the recognition/glory, but complaining about the hatred, hypocrisy, and complete lack of respect of the industry towards FOSS is normal.

The backlash he got after he "dared" ask for help was completely uncalled for. I'd even say this, it's the user who does not get to complain, let's remind everyone of what most FOSS licenses include:

  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.

You get a message during `npm install` from the dev asking for funding and a job? Tough shit, you don't get to complain because you're not paying him.