Honestly, I dont see the point of a marriage system in a modern MMO. They made sense back in the early days when people actually roleplayed, games had ONE server, and your reputation and social interactions actually mattered.

These days no one would do it unless there was some in-game tangible benefit, effect, or bonus, in which case it would become mandatory in competitive play and lose whatever the original intention of the system was. Yeah, some people would still use it just to enjoy it, but that number is extremely small compared to the development time and costs involved in implementing the system.