I read on another site that Esperanto has it's own word for "computer" and immediately though well huh, who decided on it?

The history of the Esperanto word for computer is actually quite illustrative.

In the beginning there were two words 'komputero' and 'komputoro'. Neither found favour with the Esperanto speaking community, despite being listed in dictionaries, and eventually both were rejected in favour of komputilo, thereby extending the previous meaning of komputi.

Komputero was a straight borrowing from English and possibly also the term used in other languages at the time (so international). But -er is a Esperanto suffix and a komputero was clearly not an -ero of something. However this was probably over-sensitive as there are a number of roots in Esperanto which were borrowings which ended in -er, like helikoptero, reportero etc.

-Or is a pseudosuffix in Esperanto (eg redaktoro, inspektoro, akumulator) which can be used in the creation of new roots but is not freely combinable with any root like a normal suffix.

It is easy to see sometimes why a certain vocabulary initiative is stillborn, or going to be readily accepted, but in other cases the reasons for acceptance are somewhat mysterious and the explanations speculative. Nobody knows why we say, for example, 'krokodili', though theories abound.

Even in English the origin of 'computer' in its modern sense requires some explanation as the term originally referred to a person. Nowadays saying 'he is a computer' is not stating a person's job-title.

ShannonCC:
And, just out of curiosity, in a language like Esperanto, where there is no country of origin and the creator is dead, who makes new words?

The dead creator left behind rules for forming new words from old roots, and even adopting new roots (see Fundamento rule 15).

sudanglo:The history of the Esperanto word for computer is actually quite illustrative. . .

That's very interesting, thank you!