[Jim McDougall]

This is an excellent explanation Marius!
I would add that Aylward (1945) noted that the English apparently certain prejudicial attitudes concerning the dark working with metal, and believed that 'foreigners' possessed occult secrets about the manufacture of arms & armor which were outside their scope.

While this may sound 'silly' as the topic of superstition and fears and notions on the occult and 'magic' etc. are in a manner of thinking, much 'avoided' today. However it is not the fear of evil effects but more associating these long outdated beliefs with ignorance and low awareness.
In the study of arms, this has often been my experience with analysis of markings, inscriptions and often features in weapons.

It was not until the progressive posture by Henry VIII in bringing foreign armorers into England that the advent of English arms production moved ahead. Until then England had relied on Spain, France, Germany and Italy for most armor and blades.

Interestingly there were knife makers apparently, but this industry seems outside the realm of sword blades and armor. It seems odd that blacksmiths functioned as well known , and along with cutlers who mounted the blades.

In "The Sword in Anglo-Saxon England" (H.R.Ellis-Davidson, 1962. p.34), concerning sword blades as early as 9th century, "...pattern welded swords may not have been made in many workshops and as yet there is no evidence they were ever produced in England or Scandinavia, though there seems no convincing reason WHY THEY SHOULD NOT HAVE BEEN. "(my caps).

There were apparently adequate resources in numerous locations in England, as seen in the later developing industry of blade making.
Interestingly despite resources, much of the steel used for forging was produced in Sweden and exported to various countries in later years. It was shortages of this Swedish steel that brought issues into Germany during the Thirty Years War.