Point taken about detail and accuracy, and I have seen some very rough and ready steamers. Based on my experince though, it seems more prevailent amongst the petrol/electric community - perhaps because of the general rule that a petrol/electric is the quickest way to get a loco up and running (no boilers, etc., to worry about, and far more off the shelf components).
However, I think the power argument is a bit exagerated. A large 5" steamer (garretts, etc) can pull 2,000+Kg trains up grades, and they might pump out 5Hp. To go from that to a car engine that puts out 50+Hp seems a tad excessive. Apart from anything else, it would completely remove any element of skill on the part of the driver.
I guess it gets down to, are you doing this for interest in a hobby, or to turn a profit. (Classic difference between DVR and the rest of the AALS, IMHO).
We do it for fun, just as every other AALS club.
Yes I have ssen my share of "odd" locos in my time. What a diversity though !
Since I know a person who has built two locos that you may not like, though they are a very good representation( i've seen worst HO scale models), I can tell you for him, it is for fun. He is likely to build a 5 inch loco sooner or later for the same reason, to take aorund.
If there was a ultimate loco scale guage combo, I think there would be little interest. To each their own I say. I like all the sizes, and do not judge a guy's efforts based on my likes or dislikes.
As for a scale diesal engine, the engineering skills are beyond most people who want to build a loco, think of all the work ! You cannnotsc ale nature ( that is why your example of a garrett works - the pressure is real world. Making a diesal in scale hard, and has been done, but not withing the skill of most people. Even if there was a scale diesal, the genertor it could turn to provide enough power would be impossible, as for the motors to move the loco a equally difficlut challange. Motors that small and being that powerful are either so expensive or nonexistant.
I would love to see a scratch built Diesal-electric loco - it would be a great achievment to see. But would be able to pull people aroung a heavily graded line like we enjoy doing( the answer is it doesn't matter, the loco only has to perform for the owner to his/her espectations).
The hobby cannot exclude everyone who cannot operate a full workshop with all the tools and skills. When I see a "eyesore", I do not worry about it, I go for the loco I want to see or drive. I enjoy all sizes etc. and I know I am not alone in liking the hobby as a whole.
As for the driving experiance - well they are great. The electric traction is the least used method - most seem to go for mechanical or hrydraulic.
The electric loco perform close to the real thing - I know with former (yes I am refering to a departed friend) and current loco drivers in our club that the electriv loco performs closeer to the real thing. You have to power up gradually, look after your motoros depending on the load you have, braking is equally interesting as you roll down a hill as you apply your brakes to make sure the train's speed does not get away from you.
Diesal Hrydraulics can also be complex to drive, but I prefer the electric traction. I have found with a loco with a closed hrydraulic drive they are like a model train, dial up the forward direction you go forward, return to neutral the train stops. dial reverse etc. Boring !!! But for someone else that may be magic for them !
Once again a good debate. No one will win an agrument - and I know all I'm doing is chatting on the topic. I know I am not right, but I am not wrong either.
These are my opinions as a member of DVR, and a visitor of many other miniature railways.