Indeed, they do need to be set up correctly. I wasn't saying otherwise, or advocating any old advice. Due diligence - as with anything - is part and parcel of whatever it is you are trying to do or achieve. Maybe some people struggle, others don't so much. It very much depends on one's abilities to sort the wheat from the chaff; and of course, common sense goes a long way! Well, it's not as 'common' as it once was nowadays, it seems.
Anyway, when I first acquired my bandsaw, an old Mini Max Pro 32
(from the late 70s early 80s I think) it hadn't been in use for a good many years, didn't have a blade fitted, and the blade guard was hanging off
(I'm not sure why it's called merely a blade guard, as its function is more than that) so the whole thing I had to set up from the word go. Since doing this it's performed faultlessly, and the Tuff Saw blades I opted for I'm very pleased and impressed with. As I say, this is an important aspect, not to be underestimated.
This Mini Max is only a small machine, but it's head on shoulders better than the Fox one I had, which they claimed would cut wood up to 6" thick. Well, that was a joke, for it struggled with wood far thinner than this, and would slow down under the least amount of pressure. It was very underpowered, and after changing one of the drive pulleys
(it was slightly eccentric, so introduced rather too much wobble/vibration) it improved, but it still wasn't up to much. So I decided to source an older, more solid machine, and the one I have has the advantage of being direct drive as opposed to belt driven, so the motor spindle doesn't spin as fast to achieve the same blade speed, and hence no pulley vibration either.
All I can say is, I learned much from that initial experience, and what a better quality machine can do, which also focussed my attention on getting the thing properly set up - hence my Internet searches to help. There is some good advice out there, as well as bad, as you say. But one just needs to apply a bit of common sense and evaluate accordingly
..........though, on a side note, the disadvantage with buying older machines is weight, as far as moving them around goes. But when using, a solid machine is more reassuring to use. I really struggled to lift my Mini max, even though small, to get it into the workshop, and I'm no small guy, at over 6' 4". I don't have the luxury of a fork lift to shift stuff around