Humanizing the errors is nice, but changing that too much as you have mentioned in your article will of course provide a bad experience. Ask me how?

1. You are trying to create a new mental model with your customers with your own language.

2. The casual error messages (as mentioned) are kind of used across majority of the products, thus user spending less time to understand the error message.

3. Sometimes, the user might now get your fun & subtle language (sometimes due to lack of proficiency in English) while he/she is used to traditional error message.

In recent times, people are just complicating the field of UX by saying better UX or improved UX + forgetting some basic stuff.