Idk, They haven't had anything worth writing home about since early 990FX chipset boards. Same for MSI since the Dragon/Leo platforms.
Because they suck
Different people have different views on the matter which are limited to their own experiences.
I have always been a huge fan of ASUS. From the day they launch the Striker extreme I was hooked bought everything new that came out. Striker II extreme then Rampage 3 etc
right upto the Crosshair IV Hero which one day decided to throw up code 8 not 08 for no reason at all. I hardly even OC'd the thing.
Dead Striker Extreme Mobo
Dead Striker II mobo
Faulty Rampage III extreme mobo sound stopped working then LAN issues
Dead Crosshair IV Hero (Last Asus board I ever bought)
Oh and the Asus GTX 1070 SLi setup both GPUs had the RGB lights fail. (factory fault with these RGB tubes)
I have a Gigabyte Dual BIOS 875P from my P4 days that sill runs today.
Have 3 X 980 Ti G1s from them still run perfectly fine.
Almost every single Msi motherboard I have bought still works today. I have only had 1 failure out of maybe 12 boards that I own.
Msi Z77 GD65 (My pride and Joy) I have done terrible things to this board and it still posts like clockwork.
Msi Z87 GD65 still going strong in my brothers daily gaming rig
Currenly using a MSi B450M Mortar MAX which OC'd my 1700X to 4025Mhz and the Asus Crosshair IV Hero only did 3900Mhz.