The fact is that a steam engine is orders of magnitude more expensive to operate than a trolley, even with volunteer labor. Most likely, the effect of the trolley operation on MOT's electric bill is barely noticeable in comparison to the utility costs of operating the campus.

One thing not mentioned in this discussion is the track layout at MOT, which is very cramped and limited in relation to the operation of anything. If a small steamer like the 0-4-0T being mentioned was operational they would have to choose between steam or electric operation, as the reality is only one or the other could be operated on the track available. Operating both at the same time on the same track would be a real bad idea. Only the electric cars could use the loop track so the steam operation would have to be between the tunnel and the loop. And yes, there is also the ladder track with all the turnouts to storage/exhibit tracks that the steamer could be kept to while the electric used the route I've described, but with visitors moving around between these two attractions the safety factor has to be considered carefully. And remember that the previous director of the MOT acted in ways that drove off most of the steam volunteers after 1522 was retired.

As Mr. Goldfeder and others put it, there are many practical reasons a steamer, even a small 0-4-0T, would not be a good idea for MOT.

For any museum or organization, there may be good, legitimate, and pratical resons that weigh against operating a steam locomotive. Sometimes they outweigh the "cool factor" reasons for doing so.

Good reasoning doesn't mean the museum is "afraid to restore steam"