Agreed. But should they? I mean if I start a company with no recourse to public funds why should I obliged to employ someone I wouldn't want to work with? I understand why it is illegal. I think the ethics are debatable too. Most importantly, I think both are routinely violated under some guise such as 'culture fit', etc.
> I mean if I start a company with no recourse to public funds why should I obliged to employ someone I wouldn't want to work with?
Because otherwise certain classes of people will never be able to get certain classes of job, despite being qualified, because the people who hold those jobs are all members of another class who doesn't want to work with them.
For example, at various times both women and African Americans couldn't become doctors. There is no evidence that women or African Americans are worse at being doctors than men or white people, but the people who _were_ doctors (mostly men and mostly white) at those times didn't want to work with them, and culture suggested they were not capable of performing that profession.
Preventing discrimination against protected classes is a balancing act - balancing the infringement on the liberties of a group that systemic discrimination brings vs infringement on the liberties of an individual or single entity by saying they cannot make choices based on certain criteria. The protected classes that exist now (such as gender and race) exist because far more harm is done to far more people when they don't exist, even factoring in the fact that certain people will lose the ability to make certain choices based on all the criteria they'd like to.
But saying, "We think you're too old to be a good culture fit" is illegal while saying, "You're not a good culture fit" isn't. That's likely why companies don't say so directly, no?
The Age Discrimination in Employment Act is much narrower than commonly assumed. It only forbids discrimination against workers age 40 or older. It does not forbid ageism for being too young, nor against a 39-year-old for being too old.
More generally: discrimination in employment is legal by default and excepted only by specific prohibitions, which include race and religion and gender but not much more than that. Here are some attributes that are legally perfectly permissible to discriminate either for or against: smoking, obesity, height, glasses, alcohol use, vegetarianism, sports team favoritism.
If the culture is naive fresh-out-of-college engineers enthusiastic about being exploited by management, sure. Not sure what else it could be. Posting memes on slack?