Using the word incompetence is ridiculous. An incompetent person can't do their job and I can tell you all these people were very competent at their job. They just didn't ever have the need to learn binary math. Bitwise math is not needed for a huge portion of software.
That's like saying someone is incompetent because their entire career they have only spoken English and someone writes "el al." to them and they don't know what it means. Sure english is based on latin. Do most english speakers know enough latin to know what "et al." means? Probably. Does that make the person incompetent at their job where they only need to speak English? Definitely not.
A large portion of web developers don't have any formal education and the bootcamps and websites don't teach this stuff. As someone who has a computer science degree it seems absurd, one might even say it sounds like incompetence, but it is actually completely understandable.
Most of them can come up with the modulus solution but the bitwise operator solution is less common.
To the other comment in reply to you that talks about Amazon... yeah, that is Amazon... I work for a company with 1/100,000,000 the budget of Amazon (wild probably inaccurate guess). We don't get the people Amazon attracts. We get the people who all those other companies turned down. But you know what? With extremely few exceptions all of them have been great software developers despite not knowing how to tell if a number is even or odd using bitwise.
