Facom tools are comparable in quality to other mid-range engineer's tools such as Stahwihle, Hazet, etc. Not quite as well finished as Snap-On, Proto or Belzer are/were but still better than a lot of Chinese stuff. My ratchet and basic 1/2in socket set are Facom brand and I'm happy enough with them, although as a wood butcher I am hardly a daily trade user of such tools
I'm not sure your statement is true but likely just your opinion.
Stahwille and hazet are OE for many manufacturers (mostly German) most notably MTU, mercedes, BMW and VW group to name a few, they are designed and mostly made in Germany. They certainly are not mid range, but they cater to very different markets to snap on.
only mechanics tend to buy snap on tools, and mostly for dick measuring status down the pub. Their tools are insanely expensive for what they are. And the quality is matched by many others on the market these days for half the price.
Milwaukee tools seem to be the latest trend, and I know a few mechanics who have got fed up with paying through the nose for poor products and have switched to Milwaukee. The Milwaukee automotive power tools beat snap ons hands down and for a lot cheaper cost also.
Stahwille aim more at the precision industrial engineering end of the market and hazet generally provide specialist tools and sockets for the automotive and industrial engine market.
Proto tools are good, in the UK they are focused at the heavy industrial / civil engineering end of the market, where their tools get abused much more than they do at Dave the mechanics, and their torque wrenches are renowned for precision and longevity.