There are significant and notable cases where design is the major or one of the handful of value-driving engines of product (apple was a startup, people found value in design, jawbone, airbnb as a better experience in relation to VRBO, etc). It looks like your seemingly deriding view is of web app startups. To put this into perspective: we spend nearly 105K a year on Salesforce licenses on behalf of our company and clients. I personally think Salesforce is a particularly SHITTY, low value product because of the design. If competition gives me SF with a great UI, I find value I'm that and will pay handsomely. Value can be created by design explicitly.