Does anyone else find ROT13 spoilers as annoying as I do?

Every time I come across one, it annoys me. I have to copy the text, open a new tab to the ROT13 site, paste the text, and click the translate button.

Compare this to something like a collapsable spoiler button-box where you press a button and it expands and expands a box with the appropriate text underneath it. Even making a [spoiler][/​spoiler] tag that gave a black background and equally black text would be better than the current ROT13 solution.

Was there actually a reason for doing things this way? If so, why not just include the ROT13 translation in the javascript that’d open and close the textbox? Comments? Criticism?