You bet it was the same in Australia. There were two camps in the late 60s and well into the 70s. Those that remained loyal to the British bikes and those that were adventurous and wanted the Jpanese bikes. The Japanese bikes were so modern (and reliable) compared to the Triumph, Norton, and BSA marques. The only bikes which were considered even remotely up to par were the Trident, Rocket3 and the Commando but the Honda CB750 was the bike that changed everyone here. I owned a T100 Daytona and couldn't wait to be rid of it and bought my first Honda four in 1971 or 72 after owning a Bridgestone 350GTR. When the Z1 was released in late 72 it was all over for the British bikes. My mate who was loyal to the British bikes but finally gave in an bought a Z1 and was a convert from then on.
I look at these British bikes and see 1940s design and technology and can see why they went the way they did. Land Rovers are very similar to that design philosophy and when Toyota brought out the Land Cruiser it was all over for that marque as well even though they still make and sell that very same basic design in limited numbers
I'm surprised the museum even placed a Triumph as an exhibit when there were so many more worthy British bikes way better IMHO. The Commando, Vincent everything and Rocket 3 to name a few