As a product
Meh. Run by a bunch of academics. Good stuff outsourced to PhD kids. Technology infra outdated. The funding trends dictate that the academics retrofit everything on a batch processor. Meh.
So the "product" is doing very well. I think Spark is now almost of a monopoly in the data processing world. As a company culture I don't know.
The product gets the job done. There will be complainers as there are for any product. It's well funded because it's performing well in the current space. Like every other product, it'll eventually fall to being useless. For now, it's a very powerful product if used properly.
Shitbricks