I agree with this. I’ve seen certain Catholics in my parish who bow constantly whenever they are in the nave/during Mass. That’s fine, but I can’t help but wonder if the constant bobbing up and down actually distracts from their worship. It’s not my place to judge them, though. There are a lot of Catholics who think that Pentecostals can’t possibly be truly worshipping because of the constant hand-raising, ecstatic utterances, and even dancing, but it’s been my experience that yes, many Pentecostals are deeply in love with Jesus and are truly worshipping Him as best they know how. Same for Catholics who bow constantly–they’re doing what they feel is true worship. God looks at our hearts, not our outward appearance.
I do bow my head when passing by the Precious Blood, but it may not be obvious to most people in the pews because the head bow is so slight. I tend to lose my balance if I try to do anything other than put one foot in front of the other while I walk.

And OP, that could be one reason why people don’t bow or incline their heads–some of us have a hard time with mobility. It’s hard for those who don’t have these problems to comprehend, but I assure you that sometimes, just turning a corner can cause me to tip and nearly (or actually) fall down. So frustrating.