The customer may feel the pain to a different degree than QA, but they still feel it, so pay attention to QA's feedback. Listen to QA's experience as if you're listening to the customer. Don't wait until the customer support call complaint to hear about your software's quality.
If the product is difficult for QA to install or configure, it will be difficult for the customer to install and configure. Even if there isn't anything wrong with the software, that is it meets specifications, installation difficulties are still part of the customer's quality experience. QA can give you an idea of what that will be.
If QA have automated regression tests that suddenly start failing after a check-in, it's tempting to code around the problem, as if the automated test is the source of the failure. Developers are often quick to suggest that QA "fix" their test script to run successfully with the latest change. But that sweeps the problem under the rug. If QA's automated testing fails, the customer's automation will fail as well.
These deficiencies can be magnified by QA's experience, but shouldn't be dismissed as only a QA problem. They should be viewed as an opportunity to improve quality for the customer, because QA is the customer.
We're Customer Zero.