Why is Spanish feminine and masculine?
why does spanish have genders like buenos dias and beunas noches?
8 Answers
It is part of an evil plot to confuse students, just like the multiple forms of be, the multiple past tenses, the subjunctive, and the many prepositions that go with specific verbs. Until two centuries ago, none of these things existed in the Spanish language, but the natives decided that it made the language too easy to learn.
Because most of the languages in Europe, plus Russian, Indian, Iranian and a few others, for unknown reasons (there are several theories), somehow came up with such a thing, probably by creating gender to differentiate between males, females and non-sexual entities, and they ended up assigning the same features to all other words by means of metaphors, maybe.
English was the result of many peoples all coexisting at the same time, and since their genders were related, but they operated slightly differently from one another, communication was probably a bit messy, so eventually all genders were dropped. English, of course, used to have not only masculine and feminine, but also neutral.
The Chinese must be still scratching their heads when they learn English about why do you have soooo many tenses, since they have none, why do you add -s to form the plural, which they don't, why mouse changes to mice, which is something it never happens in Chinese, why do you need the article "the" for, which they don't have, and so on and so forth. Maybe an evil conspiracy to make their life harder when they try to learn English?
It wouldn't hurt if people learnt a little bit about languages in general.
A better question is, "Why doesn't English have genders like most languages do?".
It's not like English is without difficulties for us non native speakers. Not only you have dozens of synonyms for useless things, but the pronunciation is really, really weird, to the point that even native speakers have to ask for the spelling of names or words they don't know.
It can be said that Polish distinguishes five genders: personal masculine (referring to male humans), animate non-personal masculine, inanimate masculine, feminine, and neuter.
As regards Romance languages, Romanian has preserved the three genders of Latin.
.... and Spanish dropped Latin neuter gender. Be thankful. 
At least Spanish has two genders. I studied German and had to work with three genders. Consider yourself lucky.
Because a committee sat down and decided to make things dfficult for all us non-native speakers. 
Grammatical gender in Spanish (and other Romance languages) is a carry-over from Latin. However, it's by no means unique to Romance languages. As mentioned, German, and Danish have it and so do Russian and Arabic (none of which is a Romance language).
