I'm not an expert but I do not think that commercial viability was really something they were interested in. Again, flight inside USSR were pretty common, and

I'm not an expert but I do not think that commercial viability was really something they were interested in. Again, flight inside USSR were pretty common, and there was a demand for those flights, but only at heavily subsidized prices. So the idea probably to have this token supersonic jet as more of a demonstration of capabilities of Soviet technology, operating at a loss. Also, technological parity. I think it is more of a execution failure rather than idea. BTW, country dachas was not exactly a marker of a bureaucrat class. More precisely I believe there were two classes of dachas - small summer homes for common people and 'nomenklatura' dachas for people with personal drivers.