This kind of "your tree isn't authentic because you didn't grow it from seed and style it all yourself" attitude held American bonsai firmly in bush league territory for years. Thank God things have changed.
Good trees are mostly NOT the product of a single owner/developer/artist/whatever. They generally are the product of MANY people who contribute to them over the years. The best trees have usually been around very experienced, professional bonsai "masters" who are paid for their advice and sometimes for their work. THERE IS NO SHAME IN THAT. The shame is in bitching someone should be ashamed of themselves for trying to move their tree beyond backyard status. Doing the same wrong crap in the same wrong way gets everyone stuck in their backyard with mediocre trees.
All this sounds snobbish if you haven't been in bonsai for long. It's not.
I can't afford professional instructors or to place my trees with a handler. That doesn't mean I begrudge that opportunity to others, consider them inferior human beings or question their motives for making silly little trees. Others who seek professional advice and help for their trees IS GOOD FOR LOWLY HOBBYISTS like me.
It drives experience deeper, supports better trees overall in the U.S., increases availability of superior stock, containers and equipment, promotes the art overall. Let's just say without professionals, shows like the National and the Artisans Cup would be less than they are. The fact that both drew big numbers of extremely fine trees this year, designed and cared for by professionals and private owners alike, makes them both better shows. You only have to look back 15 years to see that.