I am not sure if I like the recent trend of keeping characters just because they happen to be popular.
From a marketing standpoint, I can see why they are doing it, but it can cause some trouble for the show if its not handled right.
Considering that they keep promoting the story as "the warring states with Riders", they sure are holding back on killing off the Riders.
Characters like Bravo, Gridon and even Sigurd should have been killed off long ago if they really wanted to follow the warring states theme.
In Ryuki, they had no problem killing off Riders left and right, and it helped making the viewer see how serious the Rider War was.