At my university, we get nothing for filing, but we get 1/3 of the take if/when the patent generates licensing. It's unclear whether or not that 1/3 starts paying out before or after all the fees spent acquiring and licensing the patent are paid off. Aside from the big upside, a key difference between universities and companies is that university patents exist for the sole purpose of being licensed. Corporate patents can also exist as a threat to your competitors. Also, it's not crazy for a company to want to acquire the biggest stack of patents it can. Despite a lack of any "novelty" as the normal world might see it, a patent filing by the company can offer nice benefits if a competitor tries to enforce a patent against the company over a similar product. The company can say "the patent office issued us a patent on the thing you're claiming to own, so that means either your patent or our patent is invalid. Let's fight."