I gotta say, I feel like the MOT concept was a really nifty idea, giving buyers plenty of variety in terms of engines (small or large tank engine? Small or large tender engine? The choice of yours!), and then letting them pick one-out-of-five (!) colour schemes they wanted.

Although, these days, brown seems to be very common, so I'd say that was the least popular one at the time. But I really liked these, they looked good no matter what carriages were behind them, and they were easy to motorise (at least, at the time, before Lego decided to change the concept for powering its trains every time it changed socks).

But after all these years, I don't still don't understand the fluro-yellow lights...

Huwbot is feeling blue.

"My Own Train" was a neat concept but I can see why it didn't do so well. A lot of people blame it on the simplistic design of the trains themselves, but I think a bigger factor is that it was a more complicated ordering system than a lot of buyers could really understand or appraise, and thus parents who just wanted a train set for their kids might have decided not to bother.

I believe I've read that LEGO Factory/Design byME didn't last for similar reasons — it needed a lot more buyers than it got to cover the cost of the packing process, and unfortunately it was difficult for the people in charge of purchases (parents, mostly) to really understand what they were paying for when it was more complicated than the purchasing process they were used to with toys or building sets.

All-in-one LEGO train sets like we see in the City theme today are definitely a valid reason for frustration among people on a budget or AFOLS who just want a few wagons or trackside structures to supplement their existing collections, but I think particularly in the City theme, they do a better job including what parents and kids looking for a motorized train set expect to see: a more or less complete play experience.