Why ? becuases its cheap no name and if it catches on fire you risk voiding all the RMA's on your motherboard and pricy asics or GPU's
why use use a cheap non branded not even rated PSU on a rig that costs you over 3k in some cases for other parts, I can't imagine why i'd want to use
at least a gold rated , server grade quality tried true and tested PSU vs that hmm

Because here we are using cheap Chinese make motherboards and these cheap Chinese made PSU sometimes are better alternative than Expensive Chinese made branded PSUs ok. And this thread is meant for experimenting, if you want everything put in front of you premade then shuuuuuu go to Bitmain Site and buy yourself there GPU miners.
For your second argument first we are the ones who are putting over 3000$ worth of GPUs on a cheap 100$ motherboards not you, if it would be a success than people like you will benefit from it or it's vise versa than it's our loss not yours......shuuuu this thread is not meant for you shuuuu...
my cheap 775 p35 motherboards with 4x pcie is serving me well from late 2013 to present, cost about ~ $30 back then, bought two pieces last week cost about ~$17 a piece now

and my hynix 900+ watts PSU (bought 5 piece this summer) at 20$ a piece (I can't find it even if i google it, bought at a surplus store) is very solid. that PSU have two separate PCBs inside and two different 12v source.
got some gold rated PSU like seasonic 1250xm (version 1) that is problematic (doesn't turn on after several hours of usage and sometimes restarts), I have a platinum seasonic 1000w (version 1) that is restarting but serving as a secondary PSU with jumper (green-black) to be always on, works very well.
majority of my gpu risers from 2013 still works. some of the usb cables are starting to have problems.
and when I experiment I still have my 280x's to try on them.

Is it possible to add PCIE multiplier to the 775 MB? If so, it is good for mining .