Has there ever been a year when the game was ruined by defense? The only time I can remember defense being almost as substantial as offense was 2014 and that was still a very fun and exciting game (especially at the championship competition).
Here’s the deal. If no (or minimal) defense were allowed this year then this game would be extremely boring. This is because cycling on offense only takes half of the field (similar to recycle rush), thus there would be no enemy interaction whether intentional or not since you never have to drive to the other end of the field.
I know from experience that it is never fun to have defense played on you, but it also provides an opportunity for the other members of your alliance to have uninterrupted scoring opportunities. Plus, teams have been getting a lot more serious about scouting in the last few years, that it will be rare that a deserving team miss out on playoff matches.
Defense allows an alliance with good teamwork to beat an alliance with objectively better robots. This is the best case scenario. It ensures that alliance selections will be just as much about selecting “good” robots as it is about selecting robots that compliment your strategy.