Languages with genders assigned for common nouns are not that unusual. It's not as though gender-assignment was a result of evolution of the language, but rather a carry-over from pre-historic times when a substantive often had a form in all three genders.
Just to byspell, if PIE had a word for "computer", *komputer-, it might appear in masc. (*komputeros), feminine (*komputera) or neut. forms (*komputerom) depending on circumstance.
Now, as languages evolved from PIE, it wasn't always necessary to maintain all three forms of the word--often, only ONE form overlived. This is sometimes the reason why PIE cognates of the same word show different suffixes/genders in daughter languages (cf. Old English wæter (neut.) Russian вода (fem.), Irish uisce (masc.))
Lastly, it's that way just because it is.
Just to byspell, if PIE had a word for "computer", *komputer-, it might appear in masc. (*komputeros), feminine (*komputera) or neut. forms (*komputerom) depending on circumstance.
Now, as languages evolved from PIE, it wasn't always necessary to maintain all three forms of the word--often, only ONE form overlived. This is sometimes the reason why PIE cognates of the same word show different suffixes/genders in daughter languages (cf. Old English wæter (neut.) Russian вода (fem.), Irish uisce (masc.))
Lastly, it's that way just because it is.