I actually enjoy that aspect of yoga, and agree it's complementary. I'm not advocating that current practitioners or practices should change at all.
What I'm saying is that I think there's an untapped market of people in the US that would be more likely to commit to regular yoga if the spiritual component adopted traditions from Christian meditation. This is based on discussions I've had with family and friends that say they mostly enjoy yoga but find the spirituality component or 'a little silly,' off-putting, or distracting.
Many US yoga studios and instructors are not dogmatic and are quite experimental and creative in their craft. There are already a number of relatively popular disciplines that de-emphasize the spirituality and focus on the fitness component (i.e. power yoga). My belief is that as yoga continues to evolve and grow in popularity in the US, some studios will reintroduce the spirituality component by fusing traditional and Christian beliefs, and that these studios will succeed in reaching a broader audience.