In reply to Marcelo.

Interesting discussion...

Working with the information we have available, if half the surveyed themes do not provide options I suggest that such themes should be excluded from the calculation because they are probably obsolete or not serious. That leaves us with half of themes using Customizer and half not. A very different headline.

To be honest, Customizer is still in a primitive state with much work to do. Simple things are not there: for example, no easy way to define a custom color palette at the bottom of the color picker and no way to set up a short list of fonts. Customizer is badly in need of its own Customizer so non-technical users can control how it works.

We should not lose sight of the fact that Customizer has great potential to be a "killer feature" that will propel WordPress into an even more dominant share. Customizer can empower non-technical creatives to design websites with no need for coding. This will eliminate the need for many basic themes and shift the emphasis of future theme developers from design to structure and function.