I was distinguishing plants from crops. I think it's perfectly fine to be growing non-native vegetables and fruits that you'd like to eat or sell.

Ah, gotcha. Makes sense.

Your points were good though! I haven't yet started gardening for fruits and vegetables but would like to at some point.

With edibles is getting tricky because everyone is eating everything… sometimes just one bite from a nice big tomato enough to ruin it…. Best to plant a lot to have for you, or plan for the ugly nettings and enclosures…. One thing that usually works are cherry tomatoes enough for you and the critters….

Same for you! Interestingly, contrary to you, my wife and I only ever gardened for produce. Didn't turn out that well with poor soil and drainage, but we tried. Wishing we had the space for it again at our current residence. And, of course, I'd actually like to have more space dedicated to native plants and biodiversity. I love bees, butterflies, moths, hummingbirds and other pollinators. Even small areas of 'nature' (if you can call specifically cultivated areas nature) really improve the enjoyment and charm of a living space.

They have the same downsides you identified for plants.

Is it fair to call it personal opinion if it's also the ecologist consensus viewpoint?

Of course. To some people, that viewpoint is what defines it as good. For others, it's beauty. For others, it's pure diversity. For others, it's minimizing the work involved. The choice of what is considered "good" here is a very personal thing.

Still, it's dismissive to place it into a class of personal opinion, when the colloquial understanding, especially here, is that there is no expectation of evidence behind it.

I think a fairer term here is 'argument'.

The other comment covered my thoughts mostly. Ecology is important. But I can't eat Blackfoot daisy. Not all gardens are there for ecosystem health. Some are for utilitarian purposes.

If the majority of your plants are native, a few non-native isn't going to hurt, assuming that they are well controlled.

Where they can be useful is that they often bloom at different times, or provide food at the start or end of the season, not furnished by native plants.

This can be really useful for supporting a wider range of species, especially with the seasons expanding/compressing.