Have you ever personally been into a naturopathic clinic to see what kind of supplements they sell and what kinds of issues they work with? Don't assume you will find any chakra/energy healing or crystal therapy there. That's not what naturopathic doctors do at all as standard practice. Much of what they use has plenty of research backing it up.
For instance, if you have pre-diabetes, you might be told to do aerobic exercise and weight training (which has been shown to lower blood sugar levels even more than cardio exercise), as well as include more cinnamon into your diet (plenty of research on cinnamon's affect on balancing blood sugar), as well as take supplements like L-glutamine, chromium, and an Ayurvedic-herb gymnestra sylvestre.
The above regimen might be used in place of a standard treatment of Metformin. Even though Metformin is considered a very safe drug, one of the things many doctors may not tell patients (I assume because they are not aware of?) is that Metformin depletes Coenzyme Q10 levels, thus if a doctor is prescribing certain drugs to patients, he/she should have a comprehensive approach to making sure that the drugs aren't depleting other factors:
http://www.drhoffman.com/page.cfm/155
In addition to the above example, there are many other very sensical approaches used by naturopaths. For example, if someone is struggling with depression, the first thing an ND (or holistic-oriented MD/DO physician) would do is to first do a neurotransmitter lab test to see which neurotransmitters are too low/high. It makes no sense for a patient to get an anti-depressant that only spares norepinephine if they have low serotonin levels. I'm sure most standard physicians don't do these tests for a reason - as that only increases the cost to the patient. But if the test could be done, that would be ideal. So if you see an ND (or holistic-MD/DO) then you would get a variety of amino acids like 5-HTP/Tryptophan to increase serotonin, or things like Tyrosine to increase dopamine levels, since these are precursors. I don't see what is so radical or dangerous about this at all. It makes sense to me. Why would someone want to take these amino acids rather than the standard SSRIs etc? Well one big issue is that the amino acids add to the system, while SSRIs don't add anything but simply are re-uptake inhibitors (meaning they slow the rate of breakdown of neurotransmitters). This can cause retention in the brain, but insufficient neurotransmitters in the gut (of which there are numerous receptors). Anyway, here's an article by an MD who explains things much better:
http://www.vrp.com/articles.aspx?ProdID=800
So I think that NDs treat many conditions in a very sensible way, and have a very useful role. It might be a concern for NDs to start prescribing pharmaceuticals in combination with natural substances (as they may not have sufficient training in pharmacology), but otherwise I think their approach has much merit. Some modalities like homeopathy still make me skeptical, but I will need to read more deeply into that before casting any judgement.