What does "Manistan" mean?

Solution 1:

In the context, I think it is just a portmanteau of man and Pakistan: Pakistan is "the land of the Pure", and the writer may mean "the land of Men", in the sense that it is a "land" where the culture and institutions are set up oppressively to protect men against all possible threats.

The ending -istan is sometimes used in an somewhat different sense, especially by right-wing organisations (I'm not going to link to it, but search for "Bradfordistan" to get a sense of their bile) but I don't think that's the intention here.

Solution 2:

As others have noted, -stan literally means "land of." But the suffix has a strong negative connotation in American English, so much so that in 2014, the president of Kazakhstan considered changing the country's name to promote tourism and foreign investment. The author of your quote seems to be invoking the image of a technological backwater full of violent fanatics, as described in the above link:

In the U.S., people broadly uses [sic] the suffix "-stan" to give a generic Oriental vibe to fictional Middle Eastern countries, as with 24's sinister Islamic Republic of Kamistan or Team America: World Police's Derkaderkastan, or to indicate backwardness and instability, with names like Doonesbury's Berzerkistan or The Onion's Ethniklashistan and Nukehavistan.