[i_v]

I think it's more up to a person's accepted risk and the nature of their business concept. One thing mentioned in the linked article is the advice that you use an existing entity if you've previously formed one for consulting or some other business. I'm 100% in favor of that since the early stages of a startup are often full of non-starts.

[crowdbloom]

Sure. I can agree with that part. One doesn’t have to form corporations for each idea, but if you are taking payments and offering a service or product that may impact another person or business then being protected is important.

[ska]

Agreed - the risk/reward seems off here. It will probably be fine, but you could potentially end up in legal hell and risk your family assets.

Why not a "parent" company you keep going indefinitely, spin off other entities as needed?

This all varies by jurisdiction of course, but last time I did something like this I filled out the paperwork myself and it cost a couple hundred only. Gets more complicated with more structure, etc. and any legal work you need - but you don't need to pay for that before it's justified.