> As an example, a lot of websites drop support for IE. If the makeup of IE users affected by it over-indexed on any particular type of race/gender/class/sexual orientation, would you classify that as inadvertent discrimination?
It's likely that until recently (maybe), that IE users were more likely to use JAWS and accessibility tools than other groups, especially if they couldn't afford upgrades to newer releases of JAWS or were stuck on enterprise computers.
> If a first version of a new website/product wasn't built to be perfectly compatible with accessibility standards, are they inadvertently discriminating against those with disabilities?
Yes, if the site is inaccessible. That said it's harder to claim that a game designed for a touch screen is inaccessible and discriminates against accessible users who prefer keyboards, perhaps, due to the hardware they use. The game might work better on a touch screen, like Fruit Ninja and might be very hard to replicate without a touch screen.
> Software bugs that may not be equally felt
Maybe. If the bug was a recent introduction of a non-binary gender field and only those with non-binary genders were affected, it could be considered inadvertent discrimination. It can also be considered a bug. Its severity depends on how long the bug remains in the system. If it's pushing a year, that's more likely discrimination in addition to poor QA practices and a likely inability to listen to user feedback.
> Is the only way to not inadvertently discriminate to ensure products are built to be optimized for every single human and use case? Every edge case needs to be solved for before launch?
I think we need to keep in mind that just because something could be discrimination doesn't mean we can't forgive and move on. Mistakes are a fact of life, and nothing's perfect. That doesn't mean we shouldn't try to aim for shipping fewer bugs, it means when we can, we fix the bugs, we listen to users, etc. It's very possible that one user's perfect app will in fact be completely wrong for another user, so pleasing everyone is impossible. It's why ergonomics has been so hard, humans aren't all the same height, etc.
Sometimes you need settings for users to adjust software to suit their preferences, such as font size. And sometimes you make font size part of the game, and it's not adjustable. If allowable under law, being inaccessible can be a choice, or it can be inadvertent. It's true some folks can get really worked up on a topic they care deeply about. It's also true that it's just software, and new software will come along eventually with different features that may please some audiences more. Or less. It all depends. :)