- Because that's the way it has always been done, perhaps.
- so the kids can see.
Here is another way to look at it, if I go to a railway yard and stand next to the rail, my eye level is six foot above the rail. Even an S truck is still taller then me. So with Bowens' rail height at 1530mm and my eye level at 1730mm, I am still 57 scale feet above the rail. Which means I can still clearly see across the roof of the goods shed.
As for the kids, I find the ones that are interested are only interested in the train. Their attention span isn't all that long and the detail in buildings and scenery aren't of much interest to them. Even my boys don't stay for more then a lap or two. I don't want to sound like I'm anti kid here, but honestly I find the first question that gets asked is "How fast does it go?" or "Can we crash em!". They will have much more fun on a U-Drive then spending time at Bowen Creek. We did have one little five year old at Epping 2009 that blew our socks off with his knowledge and I will gladly lift him up and spend time with him, but to date he is the only one. I guess this is why I build my layout for me and not the kids. Matt (my eldest) is 12, and he now will stand and be interested for maybe 15 minutes but he has a little step ladder and he is fine.
This bodgey photo of some likely looking lads should give an idea.
In conclusion, my opinion is to build your layout to the height you choose and be happy with it, and don't conform to anyone else's opinion. It's your layout and you will spend more time at it then anyone, so do it for you.