The place was originally selected because of the combination of several factors: - Closeness to the equator. - Ease of access by rail. - Lack of populated/fo

The place was originally selected because of the combination of several factors: - Closeness to the equator. - Ease of access by rail. - Lack of populated/foreign areas at the path of falling booster stages. - Relative closeness to production centers. - Far enough from borders and small population around the site to make spying harder (remember that in the early days it was also an ICBM launch site). Other central Asian Soviet republics were farther south, but much worse on the other factors. Russia simply continues to use it because of the existing infrastructure and tries to gradually move its civilian space program to the new Vostochny Cosmodrome.