Disagree. The most common reason I've seen for this is the recruiters using largely or entirely automated tools to comb LinkedIn, Github, and many other sources and auto-blasting out those cold emails. They don't even look at the resume until you reply with interest. It's not (usually) the hiring manager's fault. They frequently don't even know that is occurring.

I find that practice disgusting personally and will never do it myself or condone it in others, but it does seem to work.