@fatbob, I was making a wise crack with my comment, despite the lack of a smiley.
In all seriousness, having the right equipment is critical to being able to ski well. I'd be a fool to disagree. On the other hand, working in a shop helping people choose skis as well as listening to my friends and athletes about their gear, I find that many (not most by any means) want a new ski because it is new ski so it has to be better. No other reason. The unfortunate thing is that even with changes to a particular model from year to year, this year's ski may not be necessarily be better for that individual than a previous year's model.
Most people that buy new skis (yes, most) are going to benefit from the new skis as theirs are worn out, older tech, they've moved beyond them in ability or they really are just getting better skis.
'Buying a turn' is an expression that applies to people that eschew lessons in favor of trying different 'technology' to have more fun. I'm not saying it is 'bad' or that they won't succeed in enjoying skiing more. I am, however, confident in my opinion that for many a lesson or a change of technique would make a much bigger improvement in their skiing and enjoyment than new skis.