Ah!
Well, pico brew systems may not be for everyone. But I believe here you may be confusing. They are talking about the Zymatic. The first machine they produced. It's your own recipes, or recipes you download, and your own ingredients. It makes 2.5 gallons.
You are thinking of the 2nd machine, the Pico, that uses packs. Either commercial recipes, or your own. But you always buy the ingredients from them. It makes 1.5Gal.
The next machine combines both, and can be stacked to scale the production. You can either choose your own ingredients, or buy 2.5 or 1.5 Gal packs. It should be an interesting choice for anyone really.
As for the picky/purist... well, I understand it as you get the same taste over and over again with this machine. And if you brew a pack of another company, you get pretty much that beer in return. For the few commercial packs I brewed, I have to say it's pretty close. If you follow the recipe and are careful with your fermenting.
Overall, I would say if you are picky with your beer, the PicoBrew machines will produce stable and predictable results. I wanted repeatability. If you are willing to pay the price of the system and if applicable, the price of the paks, then it may be for you.
I am curious to compare the grandfather to the Z. I am tempted by the Z2 (or Z4) but want to see it in action when they delivery...one day. As that would satisfy all my desires...flexibility, my own recipes, scalability and sometimes, brewing craft breweries paks.
Cheers,