Bad management

Sometimes in our day to day life we come across people who are bad maangers.It really demotivates when speaking to people of that sort.
My work requires interaction with a person of that kind who's attitude is as follows,

When you say that you've accomplished something (like a small work completed) thier reactions would be , instead of acknowledging/appreciating the work.

1) They'll trivialise the work by saying they've previously done this work in a much better way implicating we've not done anything new. Yes we do understand that you are experienced and we learn a lot from you , but trivilasing someone's work is not good management.There are better ways to put across the fact without trumpeting oneself in such situations esp when interacting with a subordinate.

2)Talking about other problems which are pending rather than acknowledging the work completed.Yes all of us are aware of what issues/problems are pending.You need not bring up all these at this time when all we need from you is a little appreciation for the work done.

3)Finding loopholes in the work done.Of course loopholes exists in everything.We need to find a way to fill the gap and we'll do it.Until then a little acknowledgment for the work done ,will it do any harm ?
4) There are also other types of managers i've come across who will give a lot of appreciation,but end the sentence with 'BUT'. For example You've done an excellent work on this project,you are a good leader,have good team skills BUT at the same time you should take initiative to complete things faster.The whole of first part of the sentence get negated as soon as we hear the 'BUT'
We remember nothing but the 'BUT's' when we come out of the meeting.
I feel good managers would never use the BUT word when motivating people.Some managers need to learn this !