It’s common for academics working in this field to release their software open source instead of licensing it, both as a service to the public and in order to secure support. Davis is an incredibly successful academic whose software is used absolutely ubiquitously. This approach has worked for him: he has had many industrial partnerships and support from the government.
Attribution here means supporting science. If you think that it isn’t a big deal that Microsoft isn’t properly attributing him, what you’re saying is that you think it’s OK for Microsoft to be subsidized by tax payer (and private) dollars, since that’s what’s happening here. The code is clearly identical, with the exception of a few tiny transformations which leave the functionality unchanged. Arguing otherwise is being disingenuous.