Of course not. My wife and I both post to HN, and nobody has ever criticized us for it.
It helps that we give full disclosure. If we're both involved in the same thread, whoever came in second will usually say "so there's no confusion, I'm married to [the other of us]".
That seems to be one factor some of your colleagues are missing.
> "It is simply posting from a different account."
The HN community has no problem with those who post from separate accounts for "personal" and "professional" stuff. Anonymous threads asking for legal, moral, or health advice are commonplace. Using your personal account to comment on political stories and your business account to comment on code stories is cool.
But it definitely bothers me when someone uses multiple accounts in the same discussion. pg suggests this is a pattern, not a one-time occurrence. Whether or not it's intended to be malicious or manipulative, posting to the same thread from multiple accounts definitely comes off that way. Similarly, using multiple accounts to circumvent bans so you can give your posts publicity appears sketchy.
Maybe pg, the moderators, or the algorithm made mistakes. There are better ways to respond than making multiple accounts, and there are better ways to "make this water under the bridge" than the path you've chosen in this thread.