Search Engines and the default operator AND

There are many features that make Google useful. One important reason is that the results match the request… intuitively. 

Imagine this scenario …

I want to find out what Google knows about my trance music...

I search for Franz … just Franz is too wide and I get lots of stuff about other Franz’es, so I add a term...

Franz Rodenacker - that's better, but there are still too many search results to consider, let me narrow it further

Franz Rodenacker Trance - there we go, everything related to me and my trance music. If we go to the last page we can see that there are no search results for Franz or Rodenacker or Trance, but only Franz AND Rodenacker AND Trance. 

Imagine the results if the default operator was an OR

Franz OR Rodenacker OR Trance

My search results will not get narrower when I add terms if I get an OR by default. I will then widen my search results with every word I add to the search, which is deeply counter intuitive. When I add another term to the search, I am saying "This term also applies" and I am not saying "this term is interchangeable with the other terms".  I hence want:

Franz AND Rodenacker AND Trance

So what? What does this mean? 

Searches engines should implement an AND as the default operator to be intuitive -

unless they represent an exception and have a very good reason not to.

Franz