You might be putting too much effort into it. People play games for fun and generally take an out of sight, out of mind approach to their entertainment. If someone quit the game or just dropped out of sight, their online friends would wonder what happened to them for a few weeks, and then promptly forget they ever existed, unless they're friends IRL or something.

Everyone has different expectations of what their level of commitment is to the game or their social groups within it. It sounds like your guildies have a slightly lesser degree of commitment than you do. It may be less frustrating for you if you left them to their own devices more often.