This may not have been put in the most diplomatic way possible, but I think the last sentence has merit. My first reaction upon reading the chapter was "wow, Harry did a masterful job of manipulating the hell out of the Malfoys" (not that the manipulation will be to the Malfoy's detriment, but that's beside the point). Then I find out that people are impressed with the competence of Lucius Malfoy and therefore sexism? I suppose it was good that Lucius wasn't blinded by irrational hatred or greed, but that's an awfully low bar to be setting for characters that impress you. He walked in with one plan that Harry saw through in a second.

I anticipate a few possibly short scenes where Harry does basically the same thing and manipulates Bones and Madam Longbottom into supporting him as well. If this scene is being held as evidence of sexism, the laws of evidence tell me those scenes should be held as evidence against, but somehow I don't see it happening that way.

That said, if other people can see what they're looking for then so can I, but that's my take.