Can't we all just get along? and other worthless sentimentality

I notice bumper stickers.  Sometimes they are funny, sometimes they try to be powerful and inspiring but end up being hokey ("God is my co-pilot" anyone?), but usually, they are lame.  Christians have cornered the market on this:

These are indeed classics, but we Christians aren't the only ones:

"What's wrong with the "coexist" bumper sticker?  It's simply a statement of what is happening every day that "we all" continue to exist on the same planet at the same time: we coexist.  What it's trying to say is "all religions ought to coexist peacefully, respectfully, and ought not to criticize the adherents of other religions or their beliefs and practices."  

Then there's this, which is a little harsh and oversimplified (not to mention fast and loose with stereotypes)...

This one proves the point I'm getting at.  Does anyone who knows anything about these religions really believe that peaceful, argument-free coexistence is possible?  Different religions are not different roads to the same place.  They drastically contradict each other on foundational beliefs.  I offer this quote from Steve Turner, speaking about modern culture: "We believe that all religions are basically the same; at least the ones we read were.  They all believe in love and goodness.  They only differ on matters of creation, sin, heaven, hell, God, and salvation."  

There is nothing wrong with discussing and arguing (not in a hot-tempered or hateful way) about differences in beliefs, evidences for the truthfulness or superiority of one's beliefs, and why someone else's beliefs are wrong or impractical.  The WAY we discuss and argue matters, though.  Christians are to speak the truth in love; we are to let our conversation be always full of grace, seasoned with salt, so we will know how to answer everyone, and we are supposed to be ready to defend our faith with gentleness and respect (see Ephesians 4:15; Colossians 4:6; and 1 Peter 3:15).

So, can't we all just get along?  No, we can't, if "getting along" means blindly accepting everyone's beliefs as true and equally valid, even if they're patently contradictory, having to like and embrace other "truths" like "all religions are roads to God," and being forced to accept the redefined notion of tolerance, which has come to be synonymous with uncritical acceptance.  We can't get along, and we shouldn't.  Would you say that all politicians should coexist and tolerate each other's ideas for leading the country?  All politics are just different roads to saving America, aren't they?  They're all equally valid and you shouldn't criticize their teachings or practices, right?

We don't think politicians can pull this off.  Why, then, do we think that religious beliefs, which most sincere followers will say is more important than politics, can?