Dear Bryan;
It's because; it only takes a pinhole leak @ 60# pressure to cause a disaster and the 'newer' engine design(s) eliminate that possibility.
Your photo is that of a 40+ year old obsolete design/device.
Remote filters like this are only seen on industrial engines (generators/forklifts) and never near a heat source.
If I were to sell something like that here, today & it caught fire, I would be suied into bankruptcy.
They do filter well, but here on the 'left coast' It's a different world and there liability far outweighs any possible benefit.
Happy trails.
