There are unintended negative consequences of always choosing positive/ optimistic words, too. Part of maturing (in the spiritual sense) is developing an understanding that we aren't mono-polar in either direction, negative or positive, and that we often grow much more from seeing those things that we don't like about ourselves than always focusing on what we perceive to be positive (which itself is just a subjective interpretation that can differ from person to person).

This also holds true for what we observe in the world around us and how we choose to act around others and/or say to them in any given situation. One example of a way that we can damage another person is to always tell them that they're great at X (let's just use singing for this example), even though we're aware that they're objectively bad at it, to the degree that not a single person would genuinely agree with that assessment. To continue to affirm that they're good at singing when they actually suck will often result in them developing a real conviction that they're a talented singer, breeding a delusional person who goes on to annoy people and bring negative reactions/ consequences on themselves without being aware of it.

How does that help them? To live in a world that isn't the shared reality that we live in will almost certainly ALWAYS be a worse scenario than to know and live the truth.

A lot of the problem with the negative vs. positive debate comes down to definitions. We all have our own ideas about what is bad and what is good and where context comes into play in it. From my perspective, there are almost always ways that we can CONSTRUCTIVELY criticize people that would help them to grow better and faster than simply telling them positive things that they'd prefer to hear. But I'm also aware that it's important to not use what most would interpret as negative words when criticizing them, such as curse words or words that unnecessarily attack their character.

But that's not to say that there aren't situations when even such negative words are appropriate. It all comes down to context and having an understanding of why people are making the choices that reflect in their words/ actions (highlighting the importance of our own spiritual growth).