It's not about being one-issue.
It's conflict among those who put a greater emphasis on either political conservativism, social conservatism or fiscal conservatism across all issues.
What you are defining is definitely a form of "one issue" type of fanaticism. You cannot be a true social conservative, and override all fiscal considerations to pursue "social conservatism." Anyone who understands economics will tell you how critical are those fiscal issues to the preservation of your society. You cannot divorce them.
You cannot be a true political conservative, and not be concerned with social and fiscal issues. They are inherently interwoven with the preservation of a healthy body politic. The notion of a divorce, simply does not scan.
You are referring to people who claim to be Conservative, but are in fact focused on particular issues, at the expense of the overall concern for preserving heritage.