I found writs useful on pts for glass motifs. Hirelings on the other hand, not so much. I maxed hirelings on multiple toons for clothing, smithing or wood hirelings that only give v14 mats. That has been a real disappointment on the PTS, and one I won't waste skill points on in live.
To me the difference is that writs still have a payoff in gold, xp, surveys, and now glass motif pieces. Hirelings just suck up skill points to give things that are easily available from other sources.