I echo these thoughts.
I agree with Duncan, which is why maybe we have a disagreement on the Tich locomotive – for me, getting it to go around in circles, pulling me and possibly another body, is a challenge. My larger 3-1/2" gauge 2-8-2 is much less fun, and weighs in at close to 10x what Tich does. And, with Tich, it gets plugged up after 10 minutes of running, so time to take a break and socialize. 
I've finished my 3-1/2" gauge Shay locomotive, currently sitting in a glass case in our living room, and I doubt it'll get much use, if any. Nice to look at, though.
Like Thor – I just gave away a ST steam pump to a friend to get him kickstarted in stationary models, after he sold his large 7-1/4" one. He'll use it, I certainly won't.
I don't think I was always this way, so I accept that there are many ways to enjoy this hobby, so however one gets satisfaction from model engineering is fine by me.

Edited By John Alexander Stewart on 24/03/2019 14:32:33