Attraction doesn't have to win to accomplish what Simon wants them to.
A few years ago there was a group called 'Fighting Gravity' on America's Got Talent. They were something probably very familiar by now, but new then--a group that danced in the dark in neon glow-in-the-dark costumes, which made things appear to float in mid-air.
They did okay, but didn't win. What they DID do was create a new category of acts. In the next few years other groups, named Team iLuminate and Lightwire Theatre did similar acts, doing well each time.
Another example: Quick change acts (the magic acts where their clothes constantly change). The first of these to get on any of these shows was on AGT WAY back in 2006. BGT had a clone of that act the next year. Australia's Got Talent had one at some point after that.
The same has happened with these shadow acts. AGT had a shadow dancing group last year (made of children, actually) called The Silhouettes. They did well but didn't win. Simon and his company saw another opportunity to promote a new class of act, so they clearly sought out Shadow acts this year for BOTH AGT and BGT (AGT has a shadow dance group this year called Catapult).
The same will probably happen EVERY time something really new is found. For example, this year AGT has already had a "floating monk", who appears to levitate. I expect to see one on BGT next year.