[dragonwriter]

> liberals and academics have tended to pretend values or virtue don't really exist

No, we liberals (academic or not) jusr disagree with conservatives (who tend to share values, again, whether academic or not) on some details of what good values are (and, equivalently, what constitutes virtue.)

Disagreeing with your values is not the same as pretending values don't exist.

> However, they absolutely refuse to acknowledge that these behaviors are virtues

I know of no liberals who would disagree with the idea that community involvement and not committing crime (provided just definitions of crime) are virtues.

Marriage is a different story, but then even many strands of socially conservative Christianity (such as traditional Catholic doctrine) don't view marriage as a general virtue, but rather as a virtue specifically for those with a vocation for it, a vocation which is no more inherently virtuous than that for either religious life, priesthood, or committed (lay) single life. It's true that liberals often see additional lifestyle choices as no less virtuous than these.