Totally agree. It's a very personal thing. For us at Mobile Jazz it means to work on technical challenges, while at the same time working on "startup-like products" (e.g. Bugfender or Localname), while not having any pressure from investors and as you said spending also more time on other things in life.
This probably excludes a lot of product types that are highly competitive or time critical, but there's still a lot left to work on, especially niche products. In our case that niche are developer tools, which all came up organically as we built our own developer tools for ourselves anyway.
I'm glad you brought up the point about investors as I don't think the implications of taking money from investors gets talked about a lot. As you pointed out, more pressure to deliver and really should be used for pouring gasoline on fire instead of starting the fire itself though granted I know that seed money is required to get things going sometimes.
For some folks, a lifestyle business is better suited for them as they are looking to get more time out of their lives to do other things.
For others, a startup might be better because they have more control over whatever product/service they are providing.