. I remember a few years back J Mac/Steffi played Serena/??? in Wimbledon mixed and Mac hit her a kick serve. She got ate up by the serve and had to deflect it with her hand.
I'm pretty sure this match never happened.
Venus & Serena only talked about playing or beating men when they first joined the tour, they certainly don't think they can do so today. I remember a few years ago Serena saying that her male practice partner could get to any shot she hit & had no problem returning her serve, saying that none of the girls on tour could do that. I doubt he is on the pro tour.
to the op: venus & serena have been quoted as being big fans of sampras & federer, saying that they would lose to them '6-0,6-0 forever'
if you want you can show that there isn't that much ability between the 1 & 20 guy on tour(using results), so if Serena or Venus said that about Sampras, what does that mean about how they'd fare against the #20 guy?
also davenport said she can't beat her husband & capriati said she can't beat her brother. neither played on the pro tour.
tennis is always underated by the non-tennis playing public athletically. probably since it doesn't involve contact & that the playing field is so small compared to team sports(so they assume speed probably doesn't make as much of a difference)
plus going by appearances, venus & serena have bigger muscles than quite a few guys on the atp, so an uneducated viewer may think, she's stronger, so why can't she beat them? in team sports, that kind of muscle mass difference usually means the athlete is better, so its hard for them to really 'get' tennis. plus it is a sport that is 90% white, while the majority of nfl/nba is black, so there may be some subconcious feelings coming through(like if its a sport being played just by white guys, how good can they be? why can't the sisters beat them? etc etc.)
anyway, not sure why you care what they think, they can't be the first people you've encountered that feel this way?