Comment by blux
Could not agree more.
As a child in the 80s I read a programming book (can't remember the name anymore unfortunately) where the reader was encouraged to write software that is always friendly and human when it comes to communicating with the user. For example, 'Please input a number:' instead of 'Input a number:'. But also exactly the thing the writer talks about in the article; do not be lazy when it comes to pluralization.
I get nostalgic remembering that era in computing.
When you interacted with a 'computer' once or twice a week, perhaps... seeing "please" is ... neat? A 'wow' factor ("wow! It knows English!")?
Peppering input fields and forms and folksy welcoming language scattered thoughout might be useful now and then, but for systems where people are using it repeatedly hourly/daily/weekly... it's (at best) clutter and noise.