Of course you are right, but do we (English) ever say "utilisation" anyway? - it seems a very long winded way of saying "use" or "usage". I remember once an american driver asked me directions in London : I said "spin at the light", and he said, "do you mean: take a One Eighty at the intersection?". It is our nature to be monosyllabic and in theirs to be polysyllabic.
180 is a U turn. 360 is going in the same direction after spinning around once. However, I have no idea what "spin at the lights" means. It sounds like doing a burn-out (spinning the drive wheels with the brakes on so the car doesn't move, but instead produces smoking rubber and marks on the road).
Thank you, as ever, for your excellent help on these pages. However, I should say that "Its use is simple" is not very good English, whereas "It is simple to use" is much more natural. I think there may be a thin line here between 'idiomatic' and 'accurate to the language to which you're translating'. Thank you again, with gratitude and respect.
There are always various ways to say things in every language and you are learning various ways of saying that "it is simple to use". You are learning the noun "une utilisation", which translates to "use" or "utilization", as nouns as well.
You may find "c'est simple à utiliser" or "il/elle est simple à utiliser" in this course, and it will then be the right time to translate it to "it is simple to use". Eventually, you will know two French ways of saying this.