He is well known, but hardly a superstar in Australia, and even when he were racing he would get less news media coverage than would Rossi outside of his championships (and then, the coverage would also focus on Rossi)
Ti back this up, the NSW channel 9 news will discuss who may be on pole but then immediately reference where Valentino is on the grid (they do not even mention Jack Miller unless he does very well). In Australia, Rossi is more revered by followers, fans and the yellow masses alike than has been any Australian during the Rossi era in any category of bike or car racing
Interesting though that you seem so enamoured with the very person you detest so much that you follow his twitter account, but hey, who am I to judge