That does not address the issue of why it is forbidden to wear clothes of mixed fibers. The possible materials then were cotton, linen and wool. I suppose that camel hair, goat hair and sheep's wool were available.
And of course, if all the kosher laws make so bloody much sense, why did Paul decide to abolish them all at once?
I am convinced that Paul simply saw that there was a far greater possibility of converting pagans and other Gentiles, rather than Jews, who are very resistant to change in their religion. Jesus himself had practically no contact with anyone but other Jews.