I agree w/ your general premise about it being for the hobby (that's 90% of why I homebrew) but disagree with the above statement. I've known homebrewers who absolutely brew because it's cheap - I'm sure you've encountered them as well. These are the people who calculate the price per ounce and then proudly talk about how their Great Homebrew is cheaper than Crappy Macrolager. I know many people who do it because it's better than store bought, although that's becoming harder to justify as craft beer becomes better & more ubiquitous it's exceeding the capabilities of many homebrewers.
Another factor you left out, and what originally led me to homebrewing, is homebrewing because not all styles are easy to come by at the store. I started brewing because it was the only way I could taste certain things without traveling to their homelands.
Take a spin through the style guide and ask yourself on each one "how often do I see these" when they list the commercial examples. And then nite that oftentimes those examples are stretching things a bit already
Though, to contradict myself, there is a very small proportion of brewers that are doing micro kegs that are supposed to bring more of a true draught flavor to the home without the hassle of installing taps and lines and a pressurization system. It is not so great (I've only had it for Heineken and Newcastle, which aren't great beers to begin with). But it's the closest thing to "on tap" at home you can get without making a hobby of running a bar.