I have never had my colours done (though have a rough idea of what suits me), but I do agree with you, Rkep.
I always thinks it's funny when people say, quite defensively, that they'd hate to be told that they have to wear lilac, or forest green, or yellow, or whichever other colour they'd never normally wear and don't like the sound of. I mean, that's fine, you don't have to do anything you don't want to do, least of all when it comes to clothes.
But if those colours literally transform you, and people start to see an amazing looking you, before the actual colours you're wearing - and if you manage to actually make those colours look good (because they make you look so good) - then why wouldn't you, really?
My aunt had her colours done years ago, and always wears various pinks and purples and a particular shade of mid blue, and she always looks radiant - still now in her mid-70s.