It is many faceted.
"Liberal", ironically, means more willing to accept different ideas. They can be traditionalist in their leanings, wishing to roll back some of teh policies we now have, or they can be complete Stalinists, wanting more of a communistic government policy. the main reason Liberals cannot agree on anything is because they are NOT a cohesive group. They are a group that pretty much accepts things on a more individual basis.
This also makes them ripe for criticism, for what one liberal may find reasonable, another might not. TRUE liberals, even if they are not supporting a different point of view, are willing to review it on its own merits. "Liberals", meaning people who CALL themselves that, but are really just close minded individuals wanting to shift things to their particular POV, do not.
Now Conservatives are a rare breed. TRUE conservatives do NOT want to roll things back. they want things to be left the hell alone. Aside from some active campaigns, like, say, war, which are usually "temporary" things, they do not want ANY new policy.
Things are fine the way they are, leave them be. they are the damper on societal change that resist more the quicker things try to be changed. They, like liberals, are needed in a working societal system. The problem is, most people CALLING themselves "conservative" are NOT. They are retroactivists. They want to roll things back to times they remember as being better, partially due to mankind's way of forgetting the bad (a good mental survival technique).
What we have on the "right" has shifted to religious activists that want to push things towards "traditional" values which are not really 100% traditional. They are religiously based. Birth control being a prime example. the whole thing about marriage, only one person, no hanky panky w/o kiddos is something that was put in gear a LONG time ago to insure stable family growth and a plethora of progeny that was more likely to continue the cause. Doubt me? Come on over into Brooklyn and look at some of the Hasaedic (sp) communities here, where you see a woman that can't be out of her 20's carting around 506 kids all about a year apart.
Why? Simple. Kids will keep their religion when they are taught it growing up more than anything. This is not a case of divine approval, this is simple religious exposure/influence.
i guess what I am getting at here is that our definitions of Conservative and Liberal do not fit what they actually are in this day and age. What we have now are labels to make a false two-party front that only gets us people in office that really do not represent what we want them to.