To answer your original question : I think that people are not doing the due diligence checks on at least 2 points.

1/ Yes, you can find startups that promise to sell you greater products for half the price of more established companies. But with no proven track record, and no company history, believing them is more an act of faith than a sound purchase decision.

2/ These are not simple processes and the machines require support / spares. The hype factor is still way too high in the 3d printing industry : most people gloss over the fact that it is not "idiot proof" as Curious aardvark points out, and the over enthusiastic articles from the press and manufacturers certainly don't helpHowever, some manufacturers are more honest than others on that point. If you go to the printrbot website, the sales pitch of the biggest machines (Metal plus dual for instance) is clearly : don't take it if you're not experienced. For the Pro, Brook wrote that he might even interview the buyers.

The fact is that you can't buy dirt cheap machines and expect to have an iphone like experience in 3D printing today.