Why are some jobs viewed as "bad" for your career?

Sir, in my experience and opinion, any assignment where you are working above your current rank, any assignment where you are working above your current skill set, and any assignment where you are exemplifying the diversity that our Army is looking for are things we should be striving for. For the enlisted side of the house, those positions include, but are not limited to, Drill Sergeant, Recruiter, AIT Platoon Sergeant, Instructor, AC/RC, and OC.

Each of those nominative type assignments bring unique challenges. If you meet those challenges and excel, then you have checked the block for assignment diversity.

Now, there are those positions that are considered "shelving posts." What I mean by that is that those are the position that are probably commensurate with your last rank and are given to you as an alternative to QMP or a pink slip. If you receive one of those, I would hope that you have already read the writing on the wall.

Maybe it is the faithfulness in me, but I do honestly believe, and I have seen this to fruition, that if you are proactive in with your career, the Army will do right by you.

It's not necessarily going to hurt your career, but it depends on your career aspirations. The people that sit on promotion boards typically got there because they followed a certain path (i.e., operational assignments) and so when they have to choose between many equally successful officers they may tend to lean towards the ones that took the tougher (or more familiar) road. Also, they're more likely to recognize your rater or senior rater's name if they run in the same circles. The odds that they'll be impressed by your current assignment or recognize your AC/RC rater's name is probably lower. If you want to be a battalion commander, you need counsel with current or former commanders and do not accept another assignment without talking to one of your mentors. Don't just let your branch manager use you as fodder for his or her requirements. They need to fill jobs with good officers and they're good at their jobs. You need to manage your own career. A good mentor can help you navigate through the tough decisions because they've already been where you want to go and can advise you on how to best position yourself to reach your goals.

There aren't any "bad" jobs in the military. It is all relative. AC/RC isn't a bad job or a career killer. In comparison to a post Command job as an OC/T at the National Training Center, it is looked upon less favorably in a board. One of the reasons behind that are dependent on what the board guidance has (the CSA actually provides guidance of where to focus for each board - ranger experience, joint experience, AC/RC experience). Also, baord members gravitate to (as previously stated by LTC Sachariason) the "hard jobs." Those jobs that are seen as more difficult and have more responsibility. If you compare AC/RC to the OC/T position at NTC or JRTC, you can see a marked difference in the two duties. That's not taking anything away from the AC/RC job, it just isn't as demanding...and thus not as competitive. There are other jobs that would make you more competitive for promotion as well: being a JCS Intern, being a Aide-de-Camp for a 2 star, etc. All that being said, what it still comes down to is ACOMs on an OER and high enumeration. Someone with a COM profile who is an OC/T versus someone with an ACOM profile at AC/RC...the ACOM performer is going to win out. So, even though it may not seem like it, doing the best you can in any job you are given is still the key to success. I served for 2 years in a place that some people considered a career ender (BCTP...now MCTP at Fort Leavenworth). Me and two of my peers in the same unit are all Battalion level commanders now.