The difference between "Should leave current job for another" and "What job should I take" is that the first has the subject already in a job, while the other ask a second opinion on something that really can only be answered by the one asking on a personal level. The person who ask the question you refer to is asking for what I translate as an ethical judgement. Is it wise to leave a current job for a better and more tempting job? How will it look from a professional standpoint? The answer is yes, and it will not look too bad unless he/she leaves with both middle fingers raised shouting "F**k you all!".
In other words, it's an ethical question, not a personal choice question, even tho I do see your point that it looks a bit like that.