The whole point, for me, is not to vilify the Hay Allan brothers or their work, but to recognise their creations for what they are.
The underlying problem with the tartans the Hay Allan brothers devised was that they misunderstood the very nature of tartan. Tartan was simply the way that the Highlanders could bestow their love for colour and pattern onto woven cloth. It's function was decorative.
The Hay Allan brothers had the notion that tartan was some sort of heraldry and had the function of allowing bodies of soldiers to be indentified at distance.
This difference in function results in a quite different approach to tartan design.
Traditional tartans were often quite complex. Sadly I don't have digitised images of the photos I have in books of fragments of early 18th century tartans, but these were often highly complex, diffuse designs using a large number of different colours.
But here are a few 18th century tartans which are still being woven and worn:
To the Hay Allan brothers, on the other hand, tartans, since they had a heraldic function, must be simple and bold and consist of as few colours as possible. They must be able to be described verbally in a clear concise way. They also conceived of tartans as being about a number of bands of one colour placed upon a ground of another, not the complex interpenetrating nature of tartans designed by weavers. It must be remembered that traditional tartans were designed on the loom but the Hay Allans designed theirs on a drawing board.
The Hay Allan's tartan designs were inelegant and simple-minded.
They might place two equal bands upon a ground:
And three equal bands:
And, in a dramatic imaginative leap, FOUR equal bands:
(Just think of the lovely tartans which would have resulted if they had been able to make the conceptual leap to five.)
Sadly, some of the Hay Allan four-equal-band tartans were simplified copies of then-current tartans in which the four bands were narrow-wide-wide-narrow, so that an artistic well-proportioned tartan was replaced by a blockish one.
My main issue with the Hay Allan brothers is not that they were charlatans, but that they were poor tartan designers.