Absolutely. The term has a definite meaning. It refers to a software engineer with enough market awareness, copywriting savvy, and statistical ability to run a campaign full stack. There aren't that many people with this skillset, but they are valuable. By contrast, the typical person listing "marketing" on LinkedIn is just not that technical.

A good growth hacker can conceptualize and code the AirBnB/Craiglist integration; most of the people listing marketing on LinkedIn can't do that, skilled as they may be in other respects.