That's just one of those things. I've had a taxi down the Conwy Valley when I went there specifically to do it by train.
I've done FW to Glasgow by Citylink coach a number of times[1], and the scenery is easily as spectacular as it is by train, anyway, and you get a better view of it through the massive windows coaches tend to have. One particular memory, on the early Sunday morning bus, is of a man and (I guess) his son just appearing out of a field in one of the long moorland sections and flagging us down - clearly been wild camping! So if I was in the seats I wouldn't be too bothered about being bussed from Edinburgh to FW.
The issue really is people who have paid for sleeper cabins so they can actually sleep and aren't getting them.
[1] The reason being that in winter there's no Sunday morning train from FW, which means you can't get all the way back down South on a Sunday unless you take the morning Citylink to Glasgow or you fly the long stretch instead. I believe the term for this is "throwing business away" - I reckon even a permanent RRB in the timetable (in the manner of the Saturday 0200 buses off Euston) would sell tickets.
Sure!
The coach was surprisingly enjoyable thanks to a very nice, funny driver and new coach.
However, I was not looking forward to it, worried it might make me feel sick and I was only spending a week in Fort William because of the Sleeper so it was really once in a lifetime.
The journey was indeed lovely but I spent most of it asleep... which I probably wouldn't have done on the Sleeper!
I did eventually get to do it again two years later as the accommodation and owners in FW were so nice I found a reason to justify going again.
Whilst the views were amazing, being squashed in a table of 4 opposite people who got on at Queen Street so I couldn't stretch my legs in the "shabby chic" seated carriage we changed onto at Waverley after 8 hours plus amother 5 odd was unforgettable for the wrong reasons.
(Was supposed to be mk5 when I booked).
I know, there's no pleasing me.