This is why I try and get a day of the week in-guild devoted to helping lowbies. Yeah, everyday should be about supporting fellow guild members, but I find it's nice to set aside a day where it's encouraged to offer to run your alts with new low-level members or, if all else fails, do run-throughs and help them with harder quests. I find it really helps foster some community among new members and "war-bonded vets".
Of course, I'm still a lowbie in swtor, myself, so I haven't suggested this yet with my guild (don't want to seem I'm being self-serving or suggesting it for the wrong reasons), but when I get to 50 it'll be my pet project.