Yes it was not an official call for help, but someone asked. He even acknowledged that experts were already on the field, and his first reaction was to just send goods there before advancing with engineering ideas.
Following your idea why were there so many civilian divers? Why not let the Thai military do the job? That's just PR. Those attention-seeking bastards.
The guy likes solving problems and has a good team to do it as well, he did it on is own dime, so why all the fuss?
"I didn't do anything to help- I don't think saving 12 people in a Thailand cave means a lot, globally speaking." yes that's the thing you're just a neckbeard who cares shit about others and feels smug about pointing fingers on the internet. Who cares if its Bill Gates, Elon Musk or Jon Doe, if they have the resources and will, why shouldn't they try to help?