Hi,
It is legal in the UK, and important that it stays so, that clubs can choose members based on their gender. Given this, the members of HCEG have every right to make the rules for their club, and to run the club as they see fit.
As it stands, and interestingly, I understand there are more female golf clubs in Scotland than male (25 to 20). In St Andrews, until the R&A became a mixed gender club, there were five main golf clubs, with 3 being male only and 2 women's only clubs.
It was fairly widely known that the club may lose the right to host The Open if they did not allow female members, but I suspect that a number of the HCEG members who voted to keep the club as a male only facility did so because they did not like the pressure being put on them to change. The timeline for the change and the implications on redeveloping the clubhouse may also have been factors. All change introduces uncertainty, and perhaps some members also wondered how the everyday ambiance of the club may change with women becoming members, and if it may lead to a change to the foursomes golf the club cherish.
Should the club continue to not be a host venue for The Open, there may not be any significant financial impact on the club as visitor numbers and green fee takings should stay strong for the next 10 years as the course is terrific and people still want to play it.
As for the future, who knows what it holds, but I can imagine the club will revisit it's membership question at some point, and that The Open will return to the club in the future, but that will be for the members to decide.
Scott