[2021] What are your unpopular League of Legends opinions?

It's not that complicated. Lifesteal is represented internally as a decimal - 8% lifesteal is .08, so naturally if you miss a decimal place or typo and put in .80 instead you end up with 80% lifesteal instead of the intended 8%. I've worked as a professional software dev before (though it's not what I do at Riot) and I can tell you that this type of error is quite common, particularly when trying to do fast iteration and push things into a testable environment (which is exactly what happened here).

In League, most of this stuff doesn't get seen by a wide audience though as it never goes to PBE and is fixed before it leaves internal environments. This is one small case where the list was shipped to PBE immediately and so was seen (and was certainly disruptive to PBE games). A parallel here to non-game dev is that you wouldn't see this type of error in other software like web pages, mobile apps, etc., because they don't have publicly-facing non-prod environments of any kind meaning what you see is always the final product (which is not the case with League PBE).

That being said, as far as humorous internal typos go, I think I would probably put 80% lifesteal vamp scepter in the #3 or #4 spot of all-time League dev typo allstars.