"I believe it is a man thing" is not a good response.
Condescending, dismissive, etc. We have words for it.
We have the word late and the word tardy, so why do we have black people time?
These terms do something completely needless for bad reasons.
I mean...it is a man thing. The same way white people have a certain level of racial animus, men have a certain level of sexism. That's what happens when you live in a society built specifically for you.
The concept of "black people time" exists specifically because of white people stereotyping black people.
dude
You need to reexamine your assumptions.
There is a case for "it is a man" thing, but not in the way you're seeing it. Men are more likely to challenge authority, but that doesn't actually fall in line with the idea behind mansplaining. They are more risk taking, which may lead to them challenges others who society recognizes as experts. However, neither of those things fall in line with assumed authority, condescension and dismissive attitudes. A women with risk taking and disagreeableness would exhibit the same behavior. There certainly can be a legit "mansplaining", but its rare enough not to require the sexist phrasing and certainly not common enough to justify its frequency of use.
Also, society is not specifically built for any single person. I kind of need to know where you went wrong in order to address you on this any further. Perhaps I should ask why black time is stereotyping but mansplaining is not?
Aren't there fewer risk taking women historically due to how our society has been set up, specifically in relation to the roles we have established for men and women?
We don't know that is why. Across various species, similar gender patterns show up. It is also something in-grained from long ago, where we were a species still trying to make it day to day. If women were child rearing, then men had to go out to take risks in order to secure food, safety, health. Even though m/f distribution tends to come out even, a higher % of females reproduce than males. This creates reproductivity scarcity for one side that may lead to risk taking in order to pass on lineage. There's been various reasons for men to adopt risk taking as a trait. It is likely a nature+nurture outcome.
Only modernity gives us the space to question societal roles. Even in the countries that spend the most time and money to eliminate societal inequalities, the traditional gender roles come out, and some say they come out more strongly without societal tensions to test or limit biological factors.
Of course society isn't built for any single person. Our society was specifically built to benefit white people, specifically white men.
To me there's a big difference between "black people time" and "mansplaining." One phrase is the creation of a dominant group to oppress another group ("black people are lazy/can't be trusted"). The other phrase is the creation of an oppressed group, describing one of the ways a dominant group antagonizes them. As I said earlier, I don't think a large percentage of "mansplaining" examples boil down to get guy trying to shit on women. The question I'd ask is...why do a lot of guys seem to think that women can't possibly know what they're talking about when it comes to [insert topic]? Where does that mentality come from? Is it something singular, ie "this is just an individual issue that we can't extrapolate anything else from," or is it...again...something that has to do with how our society is set up, how men view themselves and how men view women?
I find critical theory to be mostly ass and this sounds like critical theory. At least crit theory without critical thinking.
There is of course a long history of race in America, but oppressor/oppressed dynamics as justification and logic has a bad history. Things are also far too complex for that. If the country or world was set up for white men then you wouldn't have so many white men struggle. There's many born-in advantages and disadvantages in life. Some advantages necessarily also come with their own disadvantage. I'd argue that white male isn't the strongest of those advantages. Being born into wealth, being born attractive, healthy and intelligent? Those are very strong predictors. They also travel across cultures and countries. Personality traits matter as well. It's far too complex to think such a large population as white males are set up for success. There's too much variance within that group in regards to various and vital traits, and too many strong-advantage traits required for reaching high success for that statement to hold weight over time. It's also very dismissive of female capability. Women have been making an impact even when they lacked many rights. They have mastered the social sphere over that same long history of human evolution, and considering that we are very social creatures, that is a strong tool to have.
So while many people may be white male, those white men are ultimately going to have to deal with being
you, the individual rather than being the sum of two traits: white, male. The you is often going to find its difficult to make it in life. It's better to be born a Hilton sister than a Billy Bob.
But I just rattled off about the bs behind oppressor/oppressed views of the world.
The guys who think a woman can't possibly known about subject X are pompous asses. I imagine that view comes from sexism or at least lack of interaction with educated women. How common is that though? And why does that justify such a malicious term as mansplaining? Because you are trying to justify malicious intent through group identities and victimization.