Here's my perspective on (internal) recruiters as someone who sits next to them at an office:
1. Recruiters tend to be really nice people.
2. All day long they talk about prospects with other recruiters almost as if they were talking about potential romantic partners. Except replace any discussion of your physical characteristics with your intellectual / linkedin characteristics. It would be weird if it weren't their job.
3. If a recruiter sends you an InMail, if you reply back (no matter what the response) it helps them as each unanswered InMail costs them money (they don't get to reuse it).
4. Their job is really hard (especially for finding developers), and they are under a ton of pressure, especially when a company is growing, to build head count. Investors really value head count growth heading into a Series B / Series C round of funding.
So, consequently, I would recommend that devs cut recruiters some slack. Be grateful we live in a time where our greatest annoyance is someone contacting us with a job opportunity.
It wasn't always like this and it probably won't be forever.