Thank you, everybody, for your insanely thoughtful responses. I am blown away. I loved reading arguments on both sides of the fence, and I agree with all your points.
I had some time to think about this and discuss it with my boss.
It is a decently big red flag for me (and our company) - enough not to proceed further irrespective of how much of a superstar the candidate is.
I'll explain our view...
For me, it comes down to mutual respect. I'd be the first to admit that our company website is crap. And even if you spent 20m on it, you'd mostly have no clue what we are working on (it is not built for the general population. It is very industry-specific). But I'd expect the candidate to say: "I checked out your site and have no clue what you guys do", at which point, I'd explain (happily).
In my line of work, thankfully, we don't need superstars. Instead, we need kind, respectful people who do a good job.
I feel a candidate not checking out the company website - is the same as an interviewer not bothering to read the candidate's resume. It is pretty disrespectful. Imagine going to an interview and the guy telling you - "Sorry, I didn't have time to read your resume. So why don't you fill me in?"
I know this happens more often than not - but we are not that kind of people at my place and would not like to have those kinds of people work for us.
And I'd hate to be in a transaction where developers feel they don't need to check out a company's website before an actual interview - just because the market is hot or they have multiple offers in hand. Irrespective of seniority or star-status 😊
Having said this, we do get very lucky and are able to attract people I consider superstars. For example, our previous
lead engineer went on to become a Django fellow. And our
current lead engineer is a Django core contributor. And they are one of the most thoughtful and kind people I have come across in my career.
I have hired people purely for aptitude over attitude in the past - knowing what I was doing. And it has always ended up poorly.
And as such, I feel that not checking out the website before an interview will continue to be a red flag for us.
Apologies for the extended essay. Again, thank you so much for taking the time to be part of this discussion.