I really do not understand your post. On one hand you say that the majority have only basic business acumen and knowledge, yet on the other you suggest that they achieve their goal to let their property whilst spending as little as possible.
Surely you cannot expect a landlord to spend more than is necessary, you realise they are in it to make their living, right?
No, the point I'm trying to make is there is a difference between the professional landlord that does things right and a lot of amateur buy to letters who are in it for the "get rich quick" attitude you see on so many of the TV programmes they try to emulate.
The professional landlords are usually in it for the long term, use professionals to look after their houses and (are more likely to) provide a good product for someone renting. The amateur landlord buys an run down house, sticks some white paint on the walls themselves and maybe purchases the cheapest kitchen they can from B&Q then tries to let it out for as much as possible.
I expect a rented house to be up to the standard of a normal house, not something with drafty single glazing, 30 year old bathrooms and mould on the walls (yes I have been to some with mould on the walls!). People wonder why nobody wants to rent in this country, the above is exactly why!