Worse yet: why "more worse" is the worst

What kind of error is it?

Redundancy Error

Why do people make this mistake?

People make this error when they try to add emphasis or clarity to the comparative form by mistakenly combining "more" with "worse". This can happen because they think of other comparisons where "more" is used correctly, like "more interesting".

What is correct?

Use "worse" by itself or "even worse" for emphasis.