These classes often encourage you to collaborate - with others in the class, and also with outside resources. That is: they would encourage you to go read the paper, so long as you cited it as a source and provided a proof in your own words you had reconstructed from memory. The idea is to encourage engagement in the community and teach people to build off of existing results, a skill often overlooked in undergrad where that would have been considered cheating.
Correlations. Language and framework preferences are driven heavily by the environment in which those languages are used. My hypothesis is that firms which still use Rails are likely to be less responsive to their developers' demands and interests in exploring new technologies and thus "working in Rails" has an association of "working somewhere which makes me use Rails."
Just curious, around how long ago was this change made? Can you find web.archive.org links for a page which was changed? I'd find them useful for discussions with my peers.
The gpg approach was available in September 2017, when I used it to setup my account. I can't tell you any better than that though, and that's part of the nature of opaque aggressive growth startups today. Things just disappear or change with no acknowledgement of the past unless it's part of the story the company wants to tell about itself today. It's reasons like this that I tend to lose all interest in a project as soon as I hear they've taken VC.
Installation of the addon was not opt-in. Receiving any form of promotional content was opt-in via about:config. There is an open conduit; anybody else could offer an addon.
So I agree that it was not neutral, because there was more of a barrier to other advertisers than to Mr. Roboto. The right thing would be to have hosted the addon on addons.mozilla.org, same as for anyone else.
But it's not a dramatically uneven playing field, given that an open conduit does exist and the reception of any actual advertising was opt-in. (I'm not saying it was ok; it wasn't. But it's not as black and white as you are saying.)
