The belts are not treated equal because the flagship shows they represent are not equal. The WHC is the title associated with SmackDown which is the little sister to the ultimate flagship of WWE programming, RAW, home of the WWE Title.
I am all for maintaining the brand extension, keeping certain wrestlers primarily on one show, having the US Title primarily on SD & The IC Title primarily on RAW. I can even see having two sets of tag titles. However, it never made sense to have the equivalent of two World Titles, there should be one clear, distinct, top title, and the champ should go back and forth defending that title against stars from both brands (the challenger can appear on both shows, then go back primarily to one brand).
The way it is now it is too reminiscent of mid 90s WCW with a World Champ & an International Champ, essentially representing the same thing (though the World Title usually got slightly better booking positioning). Eventually WCW got it right and unified the titles (at the time done as a storyline device to make World Champ Ric Flair stronger heading into his match vs Hulk Hogan, beating Int Champ Sting by pinfall on TV). A full fledged feud between the two champions culminating in a unification could be a major attraction for a premier non WrestleMania PPV like S-Series, R-Rumble, or S-Slam