If they ask, inform 'em as best as possible. No need to force the issue!
Otherwise, any interested newbie will seek & easily find tons of information on suggested first bikes on this site.
I also, sorta lean toward the rider. I wholeheartedly believe that there are many interested newbies out there that can handle a 600 as a first bike
...did I just say that! Of course that depends on a lot of factors...maturity included.