I would generally agree that any instance of discrimination by characteristics orthogonal to the performance of a given task is undesirable (if we're striving to optimize total societal benefit / output / productivity).

Attractiveness is another axis of discrimination which is frequently orthogonal to job performance (unless we're talking about jobs as a model, etc).

I never understand this argument. Wouldn't market forces, i.e. capitalism, gekko's greed-is-good argument fix this?

If there were a group of basketball players with blue eyes (that were the best in the world), wouldn't someone see the huge money potential and create a team full of blue-eyes and win the title/cup/trophy?

Maybe in many decades after the anti-blue-eye bias had been successfully mitigated such a team would be formed. But until then, money and winning is not enough.

Bias is stronger than capitalism. Some people willingly give up money to not serve gay people, for example.

Exactly, people don't act always rationally, they sometimes even act against their own interests.

Homo oeconomicus is a myth.

Sure, if a minority is a small percentage and it wont hurt you financially (much), plus you can milk it to get press (and most likely increase your profit), then I can understand that. (I think you're referring to the cake shop if I remember correctly).

However setting up shop and not serving cakes to a vast majority of your customers who are a minority is just asking for bankruptcy.

I also find it really hard to believe that there isn't one greedy capitalist that will take advantage of this situation. e.g. Huge talent shortage of tech workers. Assume that there is a cohort minority who are probably price themselves cheaper (becz they are having it harder to find a job), then there's not one person who will seize this opportunity in America?