I think your premise is basically flawed. Every DSLR maker gives a fancy marketing name to their processor chain and hypes it in press releases for new cameras.
For example, Canon calls theirs "DIGIC", and touts it as part of a their digital trinity (the other two parts being designed-for-digital lenses and the sensor).
The Canon DIGIC 5+ Image Processor brings phenomenal increases in processing speed and power. Data processing performance is 17x faster than the Canon DIGIC 4 Image Processor and features new algorithms that promote greater noise reduction at higher ISOs. Improved noise reduction provides greater image quality and a faster processing speed makes it possible to obtain high-quality shots during continuous shooting.
Nikon calls theirs EXPEED, and here's an example from their marketing material for the D5200:
The D5200 comes equipped with image-processing engine EXPEED 3, equivalent to that of higher-end models such as the D4. It processes multiple tasks in parallel at high speed while maintaining high precision to bring out the full potential of the 24.1 megapixels for both still images and movies. The image processing of the EXPEED 3 is excellent at color reproduction, gradation processing and image quality at high sensitivity. It reproduces human skin tone, eyelashes and hair more faithfully. Furthermore, from image processing and card recording to image playback and image transfer, EXPEED 3 manages massive amounts of data at high speed. Even with high ISO noise reduction and Active D-Lighting, continuous shooting speed is not sacrificed, realizing comfortable shooting. This also contributes to energy saving.
Sony's engine is named "BIONZ", and they've got a whole page about it:
For enhanced detail reproduction, Sony’s BIONZ™ Image Processing Engine infuses a sense of vibrant realism in every shot taken by an α DSLR.
It works by rendering colours captured by the α lens accurately – emphasising them with a rich layer of texture and depth just as the human eye perceives them. Working together with an Exmor™ CMOS Sensor™, BIONZ™ also eliminates noise during RAW data conversion and image processing, reproducing images in realistically vivid colour and detail.
A totally new way of enjoying photography has truly begun with BIONZ™ Image Processing Engine and the α DSLR. High-quality photos for everyone, with advanced technology that's sure to impress. That's the α attitude.
Pentax bucks the all-caps trend with "Prime". They don't quite go on about it as much, but it's still prominent in, for example, the Pentax K-3 press release:
By coupling this sensor with a newly developed PRIME III imaging engine with high-efficiency noise and image processing capacities and an anti-aliasing filter-less design, the K-3 delivers high-resolution, fine-gradation images.
And, Olympus -- I shouldn't forget that, since it's what you say you use! -- calls theirs "TruePic", and this is from the OM-D E-M1 press release:
New TruePic VII image processor
The Olympus-original image processing technology Fine Detail has evolved into Fine Detail II for proper correction of magnification chromatic aberration that differs depending on each lens's movement, and applies the appropriate sharpness processing according to the lens type and aperture value for natural, high-quality resolution. The E-M1 is also equipped with moire-removing processing equivalent to that of a low-pass filter, which helps reduce compression artifacts that tend to occur during sudden scene changes when recording a movie.
So, why does this seem less visible to you, prompting the question? I think we're still at the stage in digital camera development where sensor characteristics are a big enough differentiator that they grab most of the attention. (It's still a lot about the megapixels, although high-ISO performance has risen in prominence too.) Maybe in a decade that will slow down, and the other marketing areas, like this one, will catch up.
I do want to note that it gets at least enough attention that we do get questions about it on this site, like this one: Does Expeed 3 make D3200 better than D5100?