Fatherland brings to mind law, government and order and Germany is a country that is in favor of these things and is such often referred to as the Fatherland. Fatherland was most commonly used during the time of Nazi Germany due to the large amount of government power in the country at that time. After the fall of the Nazis, the term Fatherland stuck.
Motherland is often used to describe Russia, as in Mother Russia, because the people who come from there are fond of the environment of the country. The Russian people cater to and nurture their nationals and act in the same way that a mother would act toward her children.
Some countries, like Germany, use the masculine form of speaking when talking about their ancestors or the place they have come from. It is connotative of respect, dignity and laws. Forefathers is an example of masculinity being used to describe people of the past.
Ancestors are not often called foremothers. Mother country is a term that first came into use before fatherland, but fatherland is a more popular option for most countries, including Germany, than motherland. Russia is one of the only countries that refers to their own country as a motherland rather than a fatherland.