I understand the fustration but do you really think of the alternative would be better?
As it stands now defenders of an equal level stand a good chance. However if the buff to defense was removed the attacker would always have a huge advantage.
So what would this mean? Basically arena would be a boring grind of who is prepared to spend the most time and money resetting. If you want to keep trophies you would need to keep paying for shields.
So what you prefer? Reaching a cap where winning further becomes a real challenge or a pay to win grind feast?