If an officer asked to be dropped from Ranger school is that a career ender ? If so, why?

I wouldn't say that it's a career ender as much as it is an upward mobility stalker.

after jump school my 201 file somehow magically made it in to the RIP school group by accident. Being that I was not in an MOS that was allowed to be Ranger. I made a hard stupid choice to bring it to their attention. I was 92F/77F petroleum supply specialist. All I could think is that I would end up going thru hell only to be denied a ranger tab due to my MOS. I was really temped and I had no doubt that I had the ability and determination to make it. But we all know how well the Army is at fucking soldiers over. That and my orders where to go to home town recruiting after jump school. shortly after bringing it to the attention of the Gunny(Marine) instructor, strangely enough, my 201 file went missing. And yes we did have a Marine as an instructor at Jump School

It depends on the why the request is made.
If there are family issues that keep him from keeping his head on school.
That would be one.
A big part would be witch how far along he is.
Example if he just started at 4th rtb or father like 5th rtb. Then if he is at 6th rtb it would be losing a lot. Now if he was allowed to come back in at the beginning of the of the phase that he left and how long he was gone would make a huge difference.
the are a limited number of slots for this school.
For infantry officers my understanding if you do not have the tab when you come up for Major you better get it fast or put your papers in to change your field or to get out.

Ask yourself what would you do if one of your junior officers quit RANGER school?
RANGER school is not for the faint of heart. You must have the intestinal fortitude to C/M when the situation calls for it. I personally know of an officer who committed suicide because he was being dropped for an honor violation. Do you want to be a quitter or a winner? You decide.

Infantry officers who do not complete Ranger school due to an injury can be re-cycled and injury permitting finish the course. Those who drop from the course due to LOM (lack of motivation) or being peered out have a very difficult time being successful in the ARMY as a career officer. Competition to just get a class date is very high along with unit and soldier availability complicate just getting "in the gate". RANGER school is a leadership course that uses INFANTRY tactics to teach fundamental battle skills to Infantry Officers and Non-Commissioned Officers alike.

No it won't effect them same as seals in the Navy you just go back to your unit

In IOBC at Ft Benning a group of 2LTs discussed ways to get out of Ranger School honorably. I chose to let the commandant know that I would take a pass on Ranger School. He thanked me for my honesty and freeing up a slot for someone who wanted to go. I was assigned Mech in the 3ID and served 4 months as PL until my Ranger tabbed BN Cdr made me company XO. My next BN Cdr was a chain smoking non Ranger tabbed commander who put me in a O3 job and retired a MG. I think Ranger school is great but the Army Infantry has a way up for those that don’t wear the Ranger tab but display strong leadership.

I have to say that I have seen officers wearing the Ranger Tab that I wouldn't follow across the street to a dog fight and I've known officers without it that I would follow anywhere.

Wow. If someone believes that, you need help. Not sorry about that comment. Listen, you either have it or don’t. Realizing you don’t have what it takes, and choosing to go a different path shows me a man who knows his limits. I respect a person who does this rather than someone who doesn’t. I met a gentleman who was an AA counselor on one of the bases I served on. I ask him why he got into being a counselor for AA. He told me he was an officer and truly hated being one. He turned to alcohol for comfort and really f’ed his career up drinking. He screwed up so bad while being drunk, that the command sent him to rehab to dry out. Once he realized why he was drinking, he made a choice and finished his term and got out. He actually enjoyed the rest of his time as an officer in the military, but, still got out. He realize his limits. Not everyone can be Rambo, or John Wayne ( remember those are movies, not real life) in a certain MOS. However, you can be a Rambo or John Wayne in a different MOS. How about the cooks, supply or admin. If you didn’t have John Wayne’s or Rambos in those MOSs than the whole military would fall apart. Take pride in what you can do, realize your limits and not be ashamed of them. I hear “war stories” from the bull shitters and they look like shit to those of us who know. They only impress those who don’t know to make them feel better about themselves. A man is a man who can do what the man can do and can admit when he can’t do something. Resign and find your John Wayne/ Rambo job elsewhere in the military. They are waiting for you to lead.

Not necessarily, the reason why the officer dropped out would be the key to determining his future in the Army.