For finasteride I agree, as it decreases DHT, which is not exactly a useless hormone. It shouldn't be prescribed to anyone, as you have said. I don't necessarily agree for the Viagra/Cialis. Generally cialis is safer than viagra, with less side effects. But their mechanism of action is quite simple and doesn't cascade to a lot of other body functions, inhibition of PDE5. Viagra also inhibits PDE6 more, thats why you get a blue-ish tint to your vision, and PDE1, which is more dangerous and can cause tachycardia. Cialis inhibits PDE11 more, which affects skeletal muscles and the prostate. That's why Cialis is sometimes prescribed for BPH, and why bodybuilders take cialis as a supplement (drive more blood into the skeletal muscles, decrease blood pressure).

Getting to your point of "other psychological issues" that can result in ED. Cialis and Viagra are there for one specific case of ED, which isn't caused psychologically. If you can get an erection in the morning, while you're sleeping, PDE5 inhibitors won't help.

Of course, the less drugs you take, the better, easier on your kidneys and liver. No drugs are without side effects, PDE5 inhibitors have them, but they are mild and can be diagnosed easily. Of course, dose is important, and health issue history needs to be taken into consideration.