This is subjective: a matter of sane defaults vs consistency with matlab, but here are the arguments against
jet as default:
Research has shown that the rainbow color map is rarely the optimal choice when displaying data with a pseudocolor map. The rainbow color map confuses viewers through its lack of perceptual ordering, obscures data through its uncontrolled luminance variation, and actively misleads interpretation through the introduction of non-data-dependent gradients.
Despite much published research on its deficiencies the rainbow color map is prevalent in the visualization community. We present survey results showing that the rainbow color map continues to appear in more than half of the relevant papers in IEEE Visualization Conference proceedings; for example, it appeared on 61 pages in 2005. Its use is encouraged by its selection as the default color map used in most visualization toolkits that we inspected. The visualization community must do better.
In the absence of feedback about the data or task, the best approach for situations where color is the only display technique is probably the black-body radiation spectrum, because of its perceptual ordering and use of color to avoid contrast effects.
So this would presumably mean using one of
gist_heat as the default colormap:
This rainbow hue colormap is widely used in visualization, but produces several well-documented artifacts (e.g., Lefkowitz and Herman ; Robertson ; Rogowitz, Ling and Kellogg ). In this MRI image, for example, the colormap creates perceived contours which do not reflect discrete transitions in the data, structures in the data which fall within one of these artificial bands are not represented, and attention is drawn to the yellow areas because they are the brightest, not because they are in any way the most important.
What kind of insane colormap has the property that values spanning the extreme ends of the scale stand out less, and can’t be distinguished as easily as values in the noisy middle? Why, it’s MATLAB’s default colormap, of course!
The main issue here is that in grayscale representation, information about the ‘height’ of map regions gets lost. The center of the plot (where the highest intensity is found) has the same gray value as the border regions.