I strap all of my hives all of the time.
Beekeepers strap their hives for several reasons. One reason is to hold them intact if the wind blows them over. Another reason is to hold them intact if they are knocked over by livestock or wild animals like deer. Beekeepers who live in bear country strap their hives to deter bears from tearing them apart if they manage to get inside the electric fence. (Although I've seen photos where bears have simply crushed the hives to get to the contents.)
Another reason to strap hives is to hold the components tightly together as the hives go through changes in the weather that may tend to cause the wooden components to warp. Along those same lines, strapping the components tightly together minimizes the amount of propolis the bees have to use to chink the seams and cracks.
I strap my hives for all of those reasons, but I strap them for an additional reason that I believe is equally important.
We all know that vibration is an integral part of a colony's life and communication. I believe they use vibration in ways that we have not even begun to imagine. (This is just one of the many reasons that allowing the bees to build their own comb from scratch is so critical - but that's another story.)
Since vibration is such an important part of their life, I believe that a honey bee colony can sense the stability of their hive cavity. So, I also strap my hives to help create one solid, stable, integrated mass. I want the entire hive, even though it consists of several components, to feel like a single, solid structure to the bees.
Because my goal is to provide a hive cavity that is as close to ideal from the bees' perspective as I can make it, and because honey bees are so attuned to vibration, I believe this simple, additional step is well worth it.