It's about politeness. If somebody took care to produce a sign asking to avoid interruptions, I will think twice whether my inquiry is both urgent and important. If it is not, I will postpone it. If it is, I'll beg for pardon but interrupt.
But no, a context switch required for uttering a few words can absolutely topple the tower of concentration somebody has spent last half an hour building. Certain occupations, engineering among them, require ingesting a large amount of context and making sense of it before productive work can start. My lack of patience with a question which I could answer with 10 minutes of research (or asking someone else) may cost my colleague an hour of lost productivity. Being mindful of this helps everyone, including yourself when the roles are swapped.
But no, a context switch required for uttering a few words can absolutely topple the tower of concentration somebody has spent last half an hour building. Certain occupations, engineering among them, require ingesting a large amount of context and making sense of it before productive work can start. My lack of patience with a question which I could answer with 10 minutes of research (or asking someone else) may cost my colleague an hour of lost productivity. Being mindful of this helps everyone, including yourself when the roles are swapped.