Ugliness level is definitely a subjective criteria. But I can take liberty in generalizing it in the similar way we generalize beauty. Website of Apple is beautiful, Reddit is ugly. If you agree, we are on the same page. Till few months back, design aesthetics was one of the primary consideration I had before working on any application. But then things changed with a simple understanding – the beauty of a website or an application is not always relevant to its functionality. And then there are live examples – Amazon.com, Reddit.com, Coolmath.com, Craiglist.com, berkshirehathaway.com, HackerNews and to some extend Facebook. Also Tally (accounting software), Google docs and Wikipedia.
Unless, the purpose of an application itself is to look good, which can be a good purpose for selling say lifestyle products, it need not be aligned with a good-looking website. If the purpose is to increase sales, the primary design decisions should be derived from the sales metrics. Amazon would have come with their design after millions of split testings and optimizations. If the purpose is engagement, that should be the primary purpose and Facebook is a good example. Coolmath website conveys that they are not marketing their products and probably their target customer is more comfortable with using such website. Similarly Reddit and HackerNews meet all the test in usability and functionality for their target audience, the look and feel does not matter.
A nice look and feel of your application or website is neither a necessary condition nor a sufficient condition. Aligning it with the purpose is more important. And the only way to do it is using real metrics based on user testing. What looks cool or beautiful can serve no purpose and your target audience might not care about it.