[Tyrannosaurs]

This isn't about perception or having fun, it's about behaviour having a genuine negative impact on things.

Developers have a tendency to optimise for themselves or for what they perceive as important. Sure curt replies and cutting meetings short may be the right thing to do and often is, but in many instances they're the right thing for the developer rather than for everyone involved.

If these actions result in developers being seen as unapproachable then there are genuine consequences of that - developers will be consulted less (which long term will have a negative impact both on the organisation and on the developer who will ultimately have less influence than they might have), clarifications won't be sought or offered uninvited (which always comes back on developers) and so on.

In of itself any individual action is potentially defensible, but if the overall effect is to deter useful lines of communication within a team, that's going to work out worse for everyone.