Your argument makes great sense if you're hiring business development people, or sales people. Both of those kinds of jobs reward skill at negotiation.
But if you're hiring software engineers, it's just not true. There's a pretty strong negative bias against negotiation for most engineers, and it's not useful to the job. Being good at demanding higher compensation does not correlate with programming skill. I don't know what kind of employee you're hiring, but you really might be driving away some of the best people that way.
That said, I'd advise really just about anyone to get over themselves if they don't negotiate. You should always negotiate when you take a job, or at least try.
Any developer that needs to talk to product people, customers or other teams spend a substantial amount of time negotiating. Even when dealing with other team members you're constantly engaged in negotiation.
In my experience there's a strong correlation between ability to assert yourself and negotiate, and your ability to get your point of view through to a team and develop consensus around your solutions.
A developer can write brilliant code, but if they struggle to assert themselves enough or negotiate to get buy in for their views, they can often get steamrollered completely and the team end up shipping some mediocre solution that wasn't as hard to defend, written by someone who isn't afraid to make their voice heard.
Conversely, I've seen teams where some "high profile rock star" team member leaves, only for the rest of the team to breathe a collective sigh of relief that it's now ok to throw out his code and change most of the decisions he made that they disagreed deeply with but that they were unable to stand up to, despite in some cases outranking said developer.
As a result of those experiences, I want developers that can stand their ground and that are not afraid of fighting for what they want and believe is right, and that know how to do it in a manner that isn't confrontational but wins them respect. And no, I don't believe for a second that the meriot of the code itself is sufficient - so often it boils down to heated opinions.
But if you're hiring software engineers, it's just not true. There's a pretty strong negative bias against negotiation for most engineers, and it's not useful to the job. Being good at demanding higher compensation does not correlate with programming skill. I don't know what kind of employee you're hiring, but you really might be driving away some of the best people that way.
That said, I'd advise really just about anyone to get over themselves if they don't negotiate. You should always negotiate when you take a job, or at least try.