It is mainly a matter of avoiding ambiguity.
At any moment in a Timed Automaton (TA), available transitions depend on the current location and the current clock valuation. Thus, the current state is the combination of the current control state (or location) and the current clock valuation.
If you see a Finite State Automaton as a TA with $0$ clocks, only one clock valuation is possible, and it is the same for every states. The clock valuation is thus irrelevant, and the current state is entirely determined by the current location. To simplify the vocabulary, we identify both terms.
The word "location" is often used because it is hard to mistake it for "state". But it is not uncommon to see "discrete state" instead of "location", and "extended state" instead of "state".