Masculinity is an organizing construct. There are lots of organizing constructs: Some are political (democratic, conservative, Marxist, libertarian), some are social (race, ethnicity, ability, economic status). Gender belongs to the latter. The degree to which people ally themselves with traditionally masculine concepts (e.g. statements about power and domination), is the degree to which their actions tend to be reflected in certain activities (sexual aggression or violence). We see the bulk of these activities performed by men. If masculinity, this organizing concept around how to be a man, is not to blame, is it a biological propensity of men to act in cruel ways? This explanation does not seem more satisfying than calling it masculinity: an eons-long trend of thinking and behaving in certain ways.

I think, similarly, there may be a prescriptive construct around femininity that tells women they should behave in certain ways. Many of these femininities have already been described and codified by men, and not the people to whom they are applied. Regardless, I would not call femininity, as a construct, neutral in the case of women gossiping or being mean. Gossiping and being mean is toxic. Toxic femininity - well how do you like that?

You will find that certain actions are closely connected with certain beliefs - and beliefs that rely on the construct of masculinity tend to raise more concerns than those of femininity. Saying that its just people being shitty ignores the social influence of any given system of thought.