Apart from the obvious profit motive?
Which is a very driving motive, obviously.
But can it really be true that NO shampoo bought from Boots (& their ilk) is any good?
I spent more then I ever have before on getting the colour of my hair sorted professionally recently. The dark brown has faded a lot, mostly on the middle to ends, over 5 washes, so I went back to the hairdressers today to ask her to look at it.
Basically she told me that it's because my hair has bleach on the ends (from previous highlights) and also because I didn't buy Kerastase shampoo from them to use on it, I'd just used Clairol Colour Protect (which I'd thought was fine). The turning up of the nose she did, it was ridiculous!