9 times out of 10 interruptions that I remember had nothing to do with improving others productivity but getting around what can best be thought if as systemic pathologies - meetings to convince people who should have no power over the project the project was on track, discussing schedules and projections. Rarely were the right people involved.

So be glad your interruptions have a net value. Maybe my anecdata is untypical - It would be nice to think so.

This is a non-sequitur. Paraphrasing the thread:

OP says "there is something wrong with the business world where you have to avoid the interruptions of the 9-5 to get things done"

I reply "even if nothing is wrong, the needs of others can conflict with the need for focus"

Then you reply "but most interruptions are not necessary for anybody's productivity".

That has nothing to do with my point. I'm not diagnosing the work world in general. I'm saying even if you fix all the problems, there will still necessarily be distractions in the 9-5 that an engineer might seek to avoid.

I find that it's not the necessary communication interruptions that are the problem. Of course communication is necessary. However, it's the unnecessary interruptions that are the problem. They could be rude people, poor climate control, or any number of other things. I'm not sure why business people and managers refuse to remedy these issues. It seems like so many companies are content with lower productivity.

Okay, good for you, but both you and the GP are trying to force a false dichotomy.

I am saying that a legitimate work environment where everything is relatively sane and people are respectful can still be tremendously distracting when you need heads down time.

True - which kind of indicates its not a same environment - have you tried remote working?