They're all like that unfortunately. When I bought my bike the original rubber was quite hard and had been damaged by previous owners trying to get the rubber on and off.
I bought a new one, but still really tough to stretch it over the tank tab. The tab could be a lot shorter, I guess Honda over-engineered the fixing to make absolutely sure it never came off by accident.
I use a spring puller to get mine off or the zip tie method works well.