I may be the inventor of in-browser hash-based password generation – at any rate, most of the early variants like SuperGenPass [1] credit mine [2] as the original. And I still use it for low-value sites – but I let iCloud Keychain generate, store, and sync passwords for e-commerce sites and e-mail services, for all the reasons mentioned by others here.
Maybe! archive.org's oldest capture of my page [0] is from 22 Dec 03, and doesn't have anything for Stanford's until 9 Apr 04 [1]. But I don't think they got the idea from me, since the first links to my page from blogs and aggregators came in Sep 04 after I added the bookmarklet [2].
[1] https://github.com/chriszarate/supergenpass/wiki/FAQ
[2] http://angel.net/~nic/passwd.current.html