"When you say that...is therefore already not a good field, "
That was never said. This was said:
....which is not to say your chosen line of work is not a good field now, or will not remain so for some time into the future.
"It ...becomes destructive and negative to warn others away from jobs they might find suitable and from which they can progress to higher levels."
This is what was said:
I don't say that to rain on anyone's parade. I hope you pursue that field if you want to, and I congratulate those who are thriving in those jobs now.
Nowhere was it said that coding is not a good field, or that anyone should not pursue it, or that medical records as an entire field has been ruled out.
I think the majority of readers both read and understood what was posted.