It shouldn't come as any surpise that people are more comfortable with the concrete than they are the abstract (substitute comrehensible and incomprehensible if so desired).
Is there anything inherently incorrect about using the senses to move one in the direction of correct understanding of the incomprehensible?
Please note that I am not suggesting about relying on our senses to determine truth (which has revealed itself unto us) or reality (as the senses are far more limited than reality).
For instance, Soothing Dave joked about praying without incense a few posts above. Obviously, one can pray without incense but when I include incense as part of my prayers, it does help reinforce the knowledge that this is something that is completely set apart from anything else that I do.
There is also something about such actions as lighting a candle and preparing the incense and going to my family's prayer corner with its icons that helps me really prepare for my prayers. Does that make any of this a crutch? I don't believe it does as it has never become required.