Let me expand one reason. Bureaucracy. The engineers or even managers you talk to may not have the authority/incentive to be honest with you. The directive from above will be to sugar coat anything they utter.
This has happened to me before :-). I was called a "traitor" (to whom?) and "elitist" for saying something similar to this in another forum.
I don't mind. Karma (even on HN) is just a number on a webpage :-P
You rarely would say "He has accumulated lot of good karma by doing good, I better see what he has to say". On HN, its a different story.
Unfortunately, it is not just a number on HN.
A recent article here revealed a hidden algorithm that makes your votes useless if you drop under the global average karma/comment.
Thus it is more likely that populist opinions have comments shown higher while yours is likely rendered less visible by being grayed out.
It's an issue of freedom of speech, and unfortunately, isn't just another "number".
"Freedom of speech" is not a guarantee that you can post some a comment on some web forum and have it be seen, its a guarantee that if you do, and it is, that your government won't punish you for it.
I realize that freedom of speech in the US doesn't apply to private establishments, but I would expect HN to hold a higher standard than say a conservative Christian forum.
And keep in mind that one of PG's goals is to reduce the herd mentality.
Just because I named 2 dubious uses of free speech, "slander" and "assasination", doesn't mean that the laws can't be twisted to clamp down on more legitimate issues: such as revealing corruption in the government which can be construed as libel in the US.
Overall, I am disappointed in the attitude of HN readers like you who take freedom of speech lightly.