Some attacks on HCI are really general problems of technology transfer. There is no linear relationship between discovery and products in any field. The transfer may be solely at the level of trained personnel. By being here we are paying UK taxes etc. and bringing on the next generation of graduates - and good graduates will give our industries a competitive edge. One other outcome of having an academic HCI community could be public education.
Major companies are able to sell some very poor products.
Usability is still not a major issue when people come to buying a product. The consequences of this are not catastrophic, but can frequently be annoying. Harold Thimbleby has argued that HCI researchers should be teaching the public about usability to help them complain, and so improve the quality of industrial products. However, he also argued that cultures are almost impossible to change and take centuries to do so. For instance, though Mrs Thatcher may have changed some elements of our society, she did so only on a superficial level.