I think the larger context of the world of the Hebrew prophet should be borne in mind--to seek righteousness would probably be tantamount to "strive for upright conduct" in the ancient world--and that would include seeking Justice for the poor and oppressed, etc., a popular theme for Hebrew prophets. Seeking righteousness would likely be seen as part of striving for a virtuous life, whether as exemplified by one's business dealings, treatment of family and other people, whether one made apprpriate religious (ritual, Sabbath, Commandments) observations, etc, although the last were not to be stressed over and against the former.
If you want a modern extrapolation, from my own (humble) view at any rate, its easy to see what really helps people and what doesn't--selling them WT and awake magazines (or not selling, you know what I mean), and wasting their time teaching false doctrine is seeking righteousness at all--and it certainly isn't anything done conscious of a reward. It is virtue for virtue's sake, because it is the right way to treat people, and of course, the prophet says it is part of divine command.
I think when anyone starts making some kind of economy of decision-making, or sets conditions (I'll do this IF I get rewarded) then the point is lost entirely. Whether there is a tangible reward that you can point to, at least for modern humanists and egalitarians should be quite beside the point, although I think Christians might disagree. Some people start with the question over right conduct, 'but what's in it for me?' And if they are asking that question, it's not likely that the right conduct contemplates 'seeking righteousness' at all, because it's seeknig a reward.
