Because, according to the article, only the women had their hair removed. The men did have pubes.
In ancient Greece, whether you were a hairy alpha male or a gorgeous and effeminate power bottom, the gents were generally allowed to let it all hang out. But when it came to depicting the female body, she was always entirely pubeless.
You forgot the second part, which really justifies his fears. The whole quote:
And apparently, the stings and the smell are like markers for other wasps to attack (according to an expert in the article).