I also like such features.
I will almost stretch it so far, that it is such features which gives the "feeling" of that you are in command of what is simulated. (Of cource not just this one alone, but together with other small features, which I miss in this game).
One answer to why this is not simulated is that it is not realistic that you can start and stop the engine with a button(This answer comes from moderators here.). But, is it more realistic that the engines are simulated as perpetual motion machines? My opinion is that it is not. I also of cource agree with that it is not 100% realistic that you start and stop with a button, but with little fantasy can you see it as a command to the engine room. Just my opinion.
Another such feature is refueling. I saw a You tube review of SSE, in the begining of the video so is the reviewer saying that he can not see the fuelmeter, but he think there is one cause it is a 'simulator-game' he said. And the answer I have got why this is not simulated is cause modern ships do not need to refuel so often so it is not necessary to simulate. But, I think it is. The only difference between a Nuclear engine and a 2hp engine is the time they can run before refueling.
This is again my opinion and others have other opinions.