The entire point of raw files is to save the full unprocessed output of the sensor, there are no programs that edit raw files because if you do any editing it's no longer the raw output and you are better off generating a TIFF from the raw and editing that.

A note about resizing - most camera sensors have a pattern of red, green and blue pixels, where each pixel is only sensitive to a single color - the raw processing program (Adobe camera raw, lightroom, aperture, DPP, the built in camera software, etc.) takes that data and creates a picture where each pixel has 3 values (red, green and blue), as a side note, every software does it a little differently.

Resizing a raw would require generating a picture (using what software? with what settings?), resizing it and then trying to create a "raw" file that would generate the new resized image - after all this processing the new "raw" would have less accurate information that a TIFF (and probably even an high quality JPEG) - so I really don't see the point of going to all that trouble to write a very complicated algorithm that would only degrade the image quality.