Why do you want your view changed? People are socialized to find other people attractive based on what their society teaches them is attractive. That's why what is attractive changes across cultures and eras. In the present era in the US (can't speak for other places), youth is considered attractive for women. So straight men are attracted to youthful women. No shit. Why do you want this view changed?

People deny it because pure physical attraction to the single most attractive woman possible is not how people make their dating choices. People date based on personality, lifestyle, attractiveness, compatibility, availability, and other such factors. So while if a straight man was shown a picture of 10 beautiful women of varying ages and asked which is the single most attractive woman of the bunch, he would probably pick the woman in her twenties, that doesn't translate to who those men date and that doesn't mean that those men are only attracted to that one woman and not a ton of other women of varying ages as well. So it's a point that doesn't really matter at all.