Acceptance & The difference between genuine good will, and phony 'niceness'

NB. For those of you that don't know, 'Metta' (otherwise known as cultivating loving-kindness). is a buddhist meditation technique where we TRY to wish other people well.
This (Amaro) passage is from a piece by a monk called Amaro in the Forest Sangha Newsletter

(Amaro)
The one theme that seems guaranteed to bring up irritation in people is metta - (loving-kindness). It's an almost sure-fire trigger for aversion to arise to start telling everyone to love everything. I find frequently when teaching a ten-day retreat, people say, 'It was fine until day eight when you did that guided metta meditation. That really set me off.' It's strange how common an experience that is.

Sometimes metta practice is taught as a Walt Disney, 'wouldn't it be nice if everything was nice' approach. It seems to be trying to sugar everything over; to turn the world into a place where the butterflies flitter around, the lion lies down with the lamb, and children pick blackberries from the same bush as grizzly bears. Something in us gets nauseated by that Walt Disneyesque image and revolts against it. Immediately we can't wait for the grizzly to swipe the head off the little three year-old, we want to torch the butterflies, and so on and so forth. We are annoyed because everything is just too sweet, too false in that kind of approach.

(Me) In AA we hear You don't have to like everyone but you DO have to LOVE everyone. Here Amaro talks about this difference from his perspective as a monastic...

(Amaro)
loving things is not the same as liking them. Having metta for ourselves or for other beings is not the same as liking everything. We often come a cropper by trying to make ourselves like everything. This is a completely wrong approach. When we taste something that's bitter and try to force ourselves to believe it's sweet this is just falsity, it's just sugaring things over. It doesn't work. It just makes the bitter even worse. It makes it nauseating as well as horrible to taste.

And later he says..
The taste of that extremely bitter, foul drink, laden with so much sugar that you could stand a spoon up in it, has stuck with me ever since. It was the epitome of a nauseating mixture. This is what it's like when we try to practice metta by liking everything. But what is really meant by metta is the heart that can accept everything, that does not dwell in aversion towards things.

So what I find is far more important, is to discover the heart which can genuinely and completely accept the way things are. We're not trying to like everything, rather we're recognizing that everything belongs. Everything is part of nature: the bitter as well as the sweet, the beautiful as well as the ugly, the cruel as well as the kindly. The heart that recognizes that fundamentally everything belongs is what I would describe as being the heart of metta, the essence of metta. If we get that really clear within us, and begin to train ourselves to recognize it, we realize that we can cultivate this quality of radical acceptance.
Even though metta is described as a brightness or radiance in the brahmaviharas, there's also this quality of receptivity that it has. There's receptivity and acceptance; a readiness to open the heart to the way things are.

(Me again)
I see a lot of fake gushy 'niceness in AA and I like this passage because it articulates what is wrong with this approach very well.
Also its a strong commentary on a lovely quality of Acceptance that we hear about every day in the serenity prayer but don't often understand how to practice very well.