Hey guys!
I usually avoid discussions about filament myself but here are some toughts in case anyone is interested to read a supplier point of view 
First, thanks for the nice comments @William_Frick
It’s a pleasure to count you in our regular customers!
Ok so regarding filament quality. I think it’s important to make the distinction between the reseller and the manufacturer.
That’s why we now only send spools with original manufacturer’s logo so that anyone know exactly wich product they have in hand.
Before blacklisting a supplier, please consider how good the service is with them. Resellers have full control over service they offer to you. Filament quality is more tricky.
Now if they only sell “nonames” filament or rebranded with resellers logo, then it’s another concern.
Filament quality is tricky for resellers as you could have 200 good spools then 2 or 3 bad spools in the lot. You want to keep spools intact and avoid humidity as much as possible so opening each one and test tolerance or try to see if it’s brittle is not something we can do as resellers.
If someone can’t use our filament because it’s really out of specs or too brittle etc, we can offer exchange. That’s what we do at Voxel Factory. First we need to recieve the bad spool so that we can confirm it’s really problematic, it’s from us and keep it for manufacturer records (pictures/print test etc). Then we offer both shipping back and new replacement spool shipping.
Maybe it’s something matterhacker would be willing to do if you ask.
On the other hand, at some point, anyone need to understand that you pay for what you get. Cheap stuff is cheap because someone cut somewhere. There’s no magic deal.
Moreover, even high quality filament can sometimes be problematic. Even MAC send defect units, nothing’s always perfect. Also dry air in winter ans humidity in summer certainly influence filament usability.
Finally we offer RepRapper Tech GITD green and blue and glowing intensity is totally batch dependant. Glow green PLA is usually the most glowing and glow blue ABS the less.
But we will soon offer another high quality glowing green wich is good news for you I guess 
Last words, please try to see what can be done with resselers before blacklisting them. They may be more comprehensive than what you think.
Cheers 