I find it hard to believe that a single button would cause you to jump ship. Especially since you claimed to love the Samsung flagships you had. Perhaps there were other frustrations the Huawei solved for you?
Why is this hard to believe? The smartphone market is currently very saturated, with only very limited differences between high-end (or even low-end) models of different brands. If one brand has something stupid (especially to the tune of "annoys me every day", like the mentioned button) it seems to me that it's fairly obvious you would switch.
Android devices are functionally pretty similar, and at the time the Huawei and Samsung scored the same ratings for their cameras and had near-as-makes-no-difference performance. So it was an easy decision. Samsung had a rage-inducing button, the Huawei did not.