I have seen scenarios with a huge diference in quality. Some scenarios do not add anything in gamepaly you cannot do with an ordinary timetable drive. In this case, why waste money to write a scenario? Scenarios do not use layers or swap engines if you buy additional content. So my suggestion is to include scenarios only in case: They offer additional gameplay you cannot add in the timetable like cold boot, refuelling, using multiple engines in one scenario Or they have a tutorial nature. In any other case I prefer to have just one or more additional timetable drives.
For my taste, there should far more scenarios that also use layers, etc. Driving the x-teenth identical service becomes boring if nothing ever happens.
To be fair to them many of the scenarios do offer something slightly different. Closed lines, weather changing, or messing about with points, or refueling, but I do agree when its complete one leg of a journey it does seem pointless, but i've noticed that they then tend to be complete one leg of the journey A- B and then take the train to the depot, or the other way from depot to station, and complete A-B? The scenarios give them the opportunity to go beyond the station which the timetable mode doesnt allow? I get Rudolf point regarding repeating the timetable journey seems pointless, but when they can add a little sparkle of variety then I am all for it. Even the IOW where its ride the train for a bit and then take over. It gives the variety. I do get bored doing the timetable back and forth etc...which is probably why I havent touched LGV for a few weeks, once you've done it, you've done it there and back you've done what there is to do. SEHS looks like its created variety with the trains and games and layers. So yay. All happy. Even if the tunnels and the metal barriers make driving the train a little sole destroying its good fun on the outside camera, you get see a lot more! Thanks DTG!
At the moment the scenarios are dealing with the lack of randomness in the timetable. They cover things like landslides blocking tracks, trains breaking down etc. Things that don't ever happen in the timetable. So I agree that if they are just a regular service then it adds nothing and indeed takes up space where something more unusual could be.