Which Change To A Character Did Purists Overreact To The Most?

We all get attached to certain versions of characters, and when they get changed or updated, it can be annoying. So we end up debating whether Constantine needs to be bisexual, or whether Thor can be a woman. But sometimes, it just gets silly. Which update to a character were purists most needlessly upset by?

Please include a picture, book cover, clip or comics panel to illustrate the change that people should have just rolled with. And please mention the name of the character, the change, and why it wasn't such a big deal. Thanks!

Top image: Heimdall from Thor. Idris Elba is clearly the best actor for that role, and he totally killed it. People probably shouldn't have worried.