That's a good point Lew. We are talking about 17th/18th century sabres, but it doesn't change anything.
But as an advocate of evil I can answer your question - they bothered, because it was cheaper
And another thought! We can agree there were in use horseshoes as an additional material during the process. But I think not only, or are they something special? I would use also spurs, broken blades etc.... So what would make horseshoes so special that Author pointed it out - nothing? a curiosity of an object? ...
