With these "house" brands the biggest problem is lack of consistency in quality. You're never quite sure what you'll get. If I take Intersport's McKinley - some things are so badly made, from worst materials, that after short use and few washes they start losing shape and properties (when washing I normally follow manufacturer's instructions). Hiking t-shirts and shirts start pilling where contact with backpack?! Or shrinking. Meanwhile some serve me for long years without issues.
I'd even say I have better consistency experiences e.g. with Hofer's Crane - which is extremely cheap, but always delivers basic usability and exemplary durability. Can't say that for McKinley, because it's not that cheap, but priced in between, and disappointed several times. But design is better than Hofer's stuff and more usable cuts.
From Quechua I have e.g. rain hat, which after first wash (per instructions) lost water repellency. Repeat: rain hat lost water repellency. But later I found out - in comments on their website - that many of their products lose water repellency after washing. And I doubt people are such idiots pouring softener and washing at high temperatures.
So I don't know what to think, because on the other hand I'm not tempted to pay 200€ for some almost basic Mammut pants.