For them to suggest that there are no more 'guitar heroes' just shows that they didn't bother asking any guitarists. I think that there are now far more 'guitar heroes' than there used to be, and maybe that's the reason for their misguided opinion. It used to be that we, as consumers of guitar music, had limited access to info about higher-profile musicians. Only the very top echelon would obtain guitar hero status (thinking Clapton, Page, Beck, Hendrix, etc.) Now, via the internet, we have access to much more information and exposure to many more players, styles and music sources. Now guys promoting themselves via YouTube are becoming 'guitar heroes', cultivating a following and influencing other players. No longer do you have to rely on record companies and radio stations to reach your fanbase.
Most of what I listen to will never get played on the radio (especially here in the United States) but many of these bands include players that I would consider as having reached 'hero' status (John Petrucci, Ty Tabor, Eric Johnson, Andy Timmons, Pete Thorn, Adrian Smith, Joe Bonamassa, Rob Scallon for a range of examples.) The 'guitar hero' is alive and well, there are just more of them and they have evolved into something a little different.
To paraphrase Paul Maud'Dib... "Long live the players!!!"