Why do so many commanders (Battalion or higher) not understand or like combat engineers?

I am in an infantry battalion as the engineer liaison Nco with the guard now. Our battalion had an attached engineer company this last time in the field. The unit had no desire to even try understanding what engineers bring to the battle space. I had company commanders tell me that when they want billets assembled they will ask for engineers, and that we have no place on recon movements, or breaching complex obstacles. Engineers with R2C2, an EOCA are completely discounted by many leaders who would rather wait hours/ days for EOD to show up to even confirm an IED.

I've only had one good experience while attached as a Sapper company in support of a unit and that was my most recent.
Other than that I noticed they, for the most part, really just don't understand how to use us. They don't want to utilize the resources on something they don't fully know how to use.

As a former Engineer Battalion Commander I think I may shed some light on this question. In my experience supporting BN TF and BCTs I believe matter goes all the way down to Company level. Maneuver company 1SGs were not happy cats about having to feed, fuel, arm and water sappers with attached equipment, and there infantrymen do not like to string concertina for their obstacles. I have had one exception. It was during Purple Dragon 98' We supported the opposing forces. It particular there was a 1SG from 1/187 IN. He had to have Company sized "Battle Stars" completed with VFP for TOWs, CSW FPs, and Protective wire obstacles. He was great! he provided sketches of the positions, and a detail to assist with carrying wire and finishing the CSW positions. At the TF level very few staff officers grasp the value for the attached engineer company. It may be due to the dual role that the EN CO. CDR played (TF ENGER/EN CO CDR). Also, because of the volume of engineer specific information in the TF OPORD and the Transport required to more the ENGR CL IV/V. At the Brigade level I found that if the CDR consults and uses the EN BN staff then you as the BDE engineer have accomplished your mission. I also think that when the supporting Engineer Platoon, Co, or BN has success early on in the exercise or deployment then the maneuver folks will value them more, but if you show-up unprepared to work and fight, and not proficient they will treat you like a bad girlfriend! Such is the lot of a Combat Engineer! "Essayons"

Because you're not "what they do." We fell under a brigade special troops battalion that converted to a brigade engineer battalion. We felt a lot of cluelessness about what we are, or what we do. Fortunately our new BC is an Engineer. Was a quite a breath of fresh air when she showed up in the field to see our training, and we could tell she knew what was going on. She may have never been a combat engineer, but she does wear a tab, so nobody is going to say a thing, even in the locker room!

Having served with and for many Commanders at those levels and higher I say that they have a great regard for Combat Engineers. We had a NG (Army all the way) Engineer Battalion assigned to us in Iraq in 2003, a PFC earned our first combat medal by crawling to his M-60 MG after being struck by an IED and held off the enemy at a bridge so that the unit could cross and set up fire suppression. He and his First Sergeant who was holding the belt did a phenomenal job and were an example to all. Combat Engineers and the Army Guard, Reserve and Active Duty are one in the same when we deploy. Commanders appreciate and respect you all equally, I know this CSM (R) does.

Hoouh!!!

Because all that engineer equipment eats up the maintenance budget. Engineers often get attached to the COSCOM or Sustainment units when senior leaders aren't quite sure where they fit in the battle space. Sustainment and Logistic folks are used to trucks and the cost of truck parts. Combat and Construction Engineer equipment parts are much more expensive so they get sticker shock pretty quickly.

I don't know about commanders but as a mechanic I can tell you that picket pounders can break stuff in incredibly creative ways. Some very difficult repairs.

You think this is a new situation? I served in 36 combat eng battalian in Korean war and only in the last couple of years have I gotten any medical coverage for what happened in conjunction to working neck deep in the cesspools that passed for rivers building pontoon bridges for 14 months. I am 88 years old and just got a total hip replacement in March of 2022!!!

In that there are 2 reasons, commanders dislike Engineers, First the best grads a West Point, are graduated as an engineer & can select a different branch As Gen. Macarthur did. AND ! Say; when a spring on a weapon is lost or damaged they go off mentally losing it, and every one runs around trying to find a spring, but when, say a belly pan on a dozer is damaged, commanders will go '..well fix it...' 'whats belly pan anyway? does it effect the mission? Most engineers enlisted types take for granted what others can't fathom !

If I understood your question correctly: Sustainment Brigades do not have a heavy maintenance company like in the older DISCOM structure. The Eng Bn FSC or BSB would provide the maintenance for your unit. I would need more information to understand the structure of your organization and support relationships to give you a better answer.