Designer fabrics or not?

What is your stance on designer fabric versus, well, not? When I first started, like many people new to quilting, I went to Joann's and bought random fat quarters of fabric basing my decision on color or design and not quality. I quickly learned that even though all of the FQs are the same price, they are not all created equal. I ended up with several low thread count fabrics that fray, sew poorly and generally make a mess of any project they are used in. Upon using better quality fabrics I appreciated the more vibrant colors and realize that they generally look and feel much better. 

Of course quality always comes with a price tag. In Alabama, at least in the Birmingham area, there are not many modern quilt shops so I do most of my shopping online (which, honestly, is fine by me). I can't afford to buy massive amounts of designer fabric retail so I watch the blogs and online shops for sales. It is satisfying to get a great deal. 

But what about stash building fabrics? 

Connecting threads was having a super sale on all solids and mirage fabrics. I have had great experience with their solids before and at $5/yd retail it is great for stash building. On the flip side there is a huge amount of peer pressure from the blogging community to purchase only designer fabrics for quilts. 

Not sure exactly where I stand on this issue. So what do you think? Why the push for only designer? I don't buy designer clothes, why should I only buy designer fabrics?