Comment by 7thaccount

It's a complex issue. He is obviously extremely intelligent and at least a decent business man. If you've never used Wolfram Mathematica before, I implore you to pick up a raspberry pi and play with the educational version. It's nothing short of magical in many ways. I still prefer Python in a lot of ways (least of all with Python being free/open), but Mathematica notebooks are nuts. You can do anything from calculus to charts, geographic visualizations, neural networks, NLP, audio processing, optimization, text processing, time series analysis, matrices, and a bazillion other things with a single command or by chaining them together. It has its warts, but is very polished.

He also did some important early work on cellular automata if iirc.

Then he wrote "A New Kind of Science", which reads like an ego trip and was not received well by the community (it is a massive tome that could have been summarized with a much smaller book). He also tried to claim discoveries from one of his workers due to some NDA shenanigans (or something along these lines iirc). The latter doesn't make him a crank, just a massive egotist, which is a trait nearly all cranks have. Sabine Hossenfelder did a video on him and how he only publishes in his own made up journals and generally doesn't use the process used by all other scientists. I think a lot believe where there is smoke, there is fire. To his credit, she also mentioned that some physicists gave him some critical feedback and he did then go and spend a bunch of time addressing the flaws they found.