I love feedback, suggestions, ideas on how to improve; in fact, I almost feel as if I’m withheld a chance to improve if I don’t get feedback.
At the same time, vague negative feedback is as useful as hindsight and fortune-tellers.
We’ve all heard it: someone who visits a fortune-teller, gets a horoscope-accurate diagnosis (“you’ll come into money but it involved a large mass of water”) and matches that to whatever happens (“I found $50 in a High-C -brand orange juice — and High-C is like High Seas! That fortune teller is so accurate”)
Vague suggestions simply allow someone to say “see? I told you not to do that” after the fact: to have been right. There’s little value in being right beyond a victory at the other’s expense, and a history of being right so that one’s advice is more easily accepted without question. It has little value beyond what hindsight gives us — trading re-use for lower acceptance threshold for accuracy. Hindsight is accurate.
Vague suggestions are an opener for conversation, but discussing a vague suggestion might involve refining it. It might shine the Bullshit Spotlight at the information and chase the smelling bits out, or might beat up an imprecise idea that has merit but is difficult to express. Discussion should be done with a certain gentleness.
Once a suggestion is less-vague, more concrete, it’s actually valuable; it would be a shame to attack someone offering genuine help, chasing away his or her idea through aggressive discussion to refine it.