"This is not tasty, this is bitter."
Translation:זה לא טעים לי, זה מר.
Agree. The לי makes this a statement about personal taste - I don't like it. Without the לי it's a general statement that this is not tasty for anyone.
Still the construction with the לי is common in Hebrew, whereas English speakers don't feel the need to clarify that it is their own personal opinion (in this case)