I think you highlighted the main issue: it's not sexism, it's simply misplaced.
Would it be 4 women and 4 men, it would still be out of context and not right. I don't know if it's more jackass or more redneck, anyway it's not something that should be encouraged.
Misplaced sexualization very often is sexism. Sexism is more than singling out a particular person for their gender; it is also presenting an environment that is unwelcoming to those of a particular gender.
"Booth babes" used to be a staple at every conference. Over the last 10 years, they've become sharply disfavored, because staffing your trade show booth with scantily-clad women with no connection to your company is a fucking creepy thing to do.
People still do it, but by this time 5 years from now, everyone who does will be a pariah, trading on shock value. Those people/companies will always exist. Their existence isn't evidence that what they're doing is OK.
Oh, I wholeheartedly agree that they have "creepy" elements.
That said, this sub-thread is more nuanced. This article wasn't written because of "booth babes" offending someone at a conference that Microsoft helped sponsor.
Would it be 4 women and 4 men, it would still be out of context and not right. I don't know if it's more jackass or more redneck, anyway it's not something that should be encouraged.