We practice permaculture/natural forest gardening, which is farming meets gardening, we do it on a small scale but some farmers are doing it large scale.
Personally, I don't see the majority of modern farming or gardening techniques to be aimed at looking after humanity or wildlife in regards to the longterm, it really is about aesthetics and profit, the funny thing is is that the majority of the farmers that have switched from modern to permaculture techniques have had more luck than before. I do realize that though that a lot of this is down to knowledge. I also don't know about farming subsidies enough to know whether if farmers do switch to permaculture whether it would affect this.
Nature was designed to work together rather than against itself.
To answer your question though, the difference between farming and gardening is usually the scale it is done at.
The majority of gardeners I know don't grow food and have another job. If they do grow food its a small vegetable patch for their families and maybe a little extra, the majority of farmers I know keep less than what they sell and do not have any other income.
'Small holdings' are 'mini' farms, really the in between of farming and gardening, usually they don't just have one focus like many farms do. A small holding might have a couple of pigs, a cow, some hens, fruit trees, vegetable patch. A commercial farm usually has one focus. I've known few farmers who have more than two things that they produce. For example, I know a farmer who concentrates on cattle. I know another farmer who only has sheep and pigs and another who only grows grains.