3d printers have gone viral, no doubt they have. Now it can be seen in homes and people printing their own mobile cases and other regular items. However, for printing a metal object or a huge model, one must take it to an established firm to get it printed.
You ask why that is. Because, number 1: The money!
There are some items we just can't afford to buy, so we give orders to the pioneering industries. (Very similar to professional recording studios; if you just want to record 2 or 3 songs, you'll book a studio and not buy one, makes sense know? )
But another reason why people prefer to print extraordinary items through big industries is because of the risk involved in printing.
For example, power surges because of excessive heating, leading to explosions.
Also, 'Selective laser sintering' printers pose danger, so most prefer to not buy it.
Now, SLS powder like oxidized is explosive once it gets into air.
On the other hand, these professional companies have this authentic setup and trained personnel's and everything else in order and systematic that it doesn't pose any threat to them. Their buildings and surroundings were especially built for this purpose, unlike our homes, which are small, covered with walls and supplies, like sugar and other food items which are equally hazardous.
If the aluminum powder is not properly filtered then it can explode. The powder is viscous when it gets into your lungs and the list goes on and on.
Lastly, even if you never had a single cigarette in your life, that SLS powder is more than capable of giving you Emphysema, which is mostly caused by smoking.
So all I am saying is be careful and don't buy a whole studio for recording only 3 songs; use your brains, if you know what I mean :) Thank you for your consideration :)