Gardeners and those in the business of gardening (designers, breeders, landscapers) can't get past the native vs. non native plant conversation to the root issue. It's seemingly impossible. It's like a Bernie Sanders supporter mentioning how they like free health care to a Donald Trump supporter -- suddenly the gloves come off and no one listens, let alone thinks outside the box.
What the plant conversation is really about is control, and the illusion that we have it in life or the natural world, and that to have control promises more freedom (and economic opportunity, which curtails freedom so often); it's a very old school idea of democracy and free market capitalism that isn't sustainable environmentally or psychologically.
Look at the control of gardens and other designed landscapes -- we make something defined by our hubris, our needs, our uses; hardly ever do the needs and desires of other species come into play, and certainly not in how addressing their needs and desires will, ultimately and exponentially, improve our lives. Perhaps we first have to spectacularly fail in any interaction in life before we can succeed -- it's just sad, depressing, and agitating that it may very well be the entire biosphere we implode. Look at how CO2 levels are disrupting pollen nutrition and harming bees, or how 1/5th of global plant species are in trouble.
Naomi Klein says climate change challenges our idea of control. "It says... all this time that you’ve been living in this bubble
apart from nature, that has been fueled by a substance that all the while has
been accumulating in the atmosphere, and you told yourself you were the boss,
you told yourself you could have a one-way relationship with the natural world.... And we can either mourn our status as boss of the world and see it as some
cosmic demotion — which is why I think the extreme right is so freaked out by
climate change that they have to deny it. It isn’t just that it is a threat to
their profits. It’s a threat to a whole worldview that says you have dominion
over all things, and that’s extremely threatening."
So often our personal and public gardens are nothing less than evidence of our bossy desires. We choose plants that are pretty to us but that will be infrequently if ever used by fauna, and have little to no ecological role to play within the larger community. We then go to extremes to defend such plants, saying they shade the soil or hey, look, a honey bee is on the bloom (chances are the plant may only offer benefits to generalist adult pollinators, and especially those it evolved with in another part of the world -- aka honey bees).
William Cronon says that nature is "the meeting place between the world 'out there' and the culturally constructed ideas and beliefs and values we project onto that world." That's also the definition of a garden / built landscape, and to me it's sad. It says nature doesn't exist apart from us, and even if we can admit that it does (something deep ecologists would love to see), it doesn't necessarily have a right to exist apart from how we use it, perceive it, or alter it. In other words, our erratic emotional perceptions dictate what nature is and how it it is, even who it's for and when.
A garden is not for us in the strictest sense. It is a place that mediates between who we are now and our greatest hopes and dreams for the future. If our hopes and dreams are for a livable planet with thriving wildlife, our gardens have to change -- just like our entire sense of freedom and equality has to change. The greatest threat to the world is not someone advocating for native plants and decrying a hosta or tulip; the greatest threat is our inability to have selfless compassion, to think beyond ourselves, and to understand other species -- even entire ecosystems -- have as much right to exist as we do individually (no matter the bathroom we use or who we marry). When we don't build that road through the prairie because we don't want to disrupt the lives there, or when we plant calico aster instead of hosta, we will have practiced the greatest form of gardening possible.