I think this is one of the core preference of my being and thinking, that we all needs to be open, honest and sincere, in all we do and say.
Take any of these three away, and we have a closed, dishonest and insincere communication and relationship, which is prone to misunderstandings, miscommunications and breakdowns in relationships.
True, in some situations, often we have to be wise in what and who we're sharing things with, but, after experimenting and thinking, I have come to the conclusion that being open, honest and sincere is applicable in all situations.
I am not saying that we become inappropriate, because inappropriate brings into context two matters: (1) timing and (2) context.
However, being open, honest and sincere, is gold in any context, when applied with respect.
Being open, honest and sincere in all we do and say encourages a good cycle of honesty and real communication, where we build upon goodness upon goodness. It is also very pragmatic, because inasmuch people have been sharing with me to withhold information/lie for convenience, it's just not good for me because I have too much to do and remember, so I end up not remembering what I have said or not said, and this makes things very confusing not only for me but for others.
That is why I prefer the open, honest and sincere approach. When people speak to me, they can expect openness and they don't need to come with a guarded perspective that they "need to defend" themselves or their ideas - if their ideas or solutions are great, I will gladly accept and implement. Or if mine is better, then use my approach.
I do this because I believe that "two or more heads are better than one" - we come together and work together, and not "I'm-smarter-than-you", and the open honesty supports and compliments that. More ideas and solutions means more ideas and solutions to use to better ourselves. And less energy and time wastage to "remember lies and deceit" - I've too much on my hands to participate in such event.