In one of my previous posts I've clearly expressed my position on the browser compatibility issue. Anyway, it doesn't mean that something written in jQuery (such as a plugin) is allowed to crash or slow down a browser without any plausible reason. Generally, when we talk about good and bad jQuery plugins we usually consider secondary aspects like code styling and documentation. These are fine features, no doubt about it, but in my opinion a good jQuery plugin should not crash or slow down a browser. Period.
I often see many plugins whose code is pure art and whose documentation is excellent crashing and slowing down Internet Explorer 8 even on local testing. You have to test your plugin before releasing it and you have to test it searching for side effects that may harm a browser. Your costumers don't care too much if your code is fluent and 100% compliant to the jQuery coding standard or if a good documentation is available. These are features for web developers. Instead, test your plugin against any possible malfunction that may cause a browser to crash or slow down. This is of maximum priority in a production environment.