And the European powders aren't? For example the European RS60 sold in Europe, not banned, which is the same as Reloder 17 which is banned?!
Protectionism, pretty typical of the EU.
What makes you think Re17 is 'banned'? No Alliant Reloder powder is non-compliant with 'Reach' and all are CE certified. After RS60 was introduced under the Reload Swiss marque, Re17 disappeared off the market presumably as a result of an agreement between Nitrochemie (manufacturer and Reload Swiss owner) and Alliant to avoid duplicate products on the market - especially as Alliant ATK can sell every pound of Re17 it packages and ships to north American customers. Much as I personally dislike (actually loathe) the EU, it has NOTHING to do with this decision.
ALL Alliant rifle powders branded as 'Reloder' (plus 'AR-Comp') are manufactured in the EU at either Eurenco Bofors in Karlskoga Sweden (which also makes Norma propellants) or Nitrochemie A.S. in Switzerland.
It is in fact a misnomer to say 'American powders' are banned. The banned products originate at three locations, only one of which (General Dynamics Corporation St. Marks Powder Co., St. Marks Florida which only makes 'ball' powders or 'hybrid ball' powders) is in the US. The majority of the banned grades are from Thales / ADI, Mulwala, New South Wales, Australia (all Hodgdon brand extruded grades), or General Dynamics Corporation, Valleyfield, Quebec Province, Canada (IMR grades other than the recently introduced and improved 'Enduron' powders).
As somebody said in an earlier post, the changes in these products are being driven far more by specification changes from military ammunition purchasers who are demanding much higher standards in terms of clean burning to reduce fouling of automatic weapons, anti-copper formulations, extreme consistency in performance, and crucially much improved temperature stability. Nammo Vihtavuori is currently in the process of upgrading its entire range to meet these standards. If it didn't, it would become increasingly difficult to sell into the US handloading market, but much more importantly it would lose most of its military business.