I have worked as a municipal planner, and am a licensed plans reviewer/Life Safety Code inspector.
The description of your difficulties with the local HOA "approval committee" is a common one. Unfortunately for the self-righteous members of the body, they have no choice but to approve your development if it meets criteria. It's very black and white, their sense of 'aesthetics' and your proposed work clashing because "it's too-big," as you said, they cannot refuse your development rights. What these people fail to see is that they are liable for their behavior, and you have legal recourse to force them to approve your plans. Not doing it can leave them liable, and they better have liability insurance for the HOA board and committees because acting like that, they're gonna need it. Because you are an HOA member, if you chose the legal path because they were obstinate, you would be suing yourself. In the end, you just want to be afforded development rights you are entitled to execute. However, getting to the point where your approval is granted sometimes entails legal costs, an unfortunate circumstance. Sometimes government building departments and town, village, municipal, or county governing bodies behave in similar fashions. They count on you not being able to afford to prefer a legal avenue, but if they are acting outside of the scope of their authority, because they don't like what you are doing, they may be civilly-liable.
I sat at one municipal review committee meeting where a female architect who wasn't even a resident of the municipality made the comment, about a petitioner for demolition of a condemned building, "if he's unwilling to renovate the building, instead of demolishing it, can't we just take the property from him?" Unbelievable! So, it happens, all too-frequently. The petitioner ended up spending more than he paid for the property in legal costs just to be able to follow the dictate of the building department who through one of their committees, had condemned the structure.
So, I'm glad to hear that you stood your ground, and were able to do what you wished. Ultimately, the body has no other legally-acceptable alternative.
Nice living in a place that will allow you to build a shop. We live in a rural neighborhood as well. Though our HOA is a bit more relaxed as we are able to have Tin cover barns with the only exception of it having Wainscoat Brick/Stone of the same type used on the house. Just for the sides that face the street.
I did get in a month long ******* match with the approval committee as I wanted a 20x60 lean off the front. They said no because they were able to use their subjective powers. They were also upset with the size of the shop as they felt it was too large for the community. At the time it was going to be 50x60. However, there was nothing in the by laws that gave them the power to reject it due to the size. But since they would not allow the Lean I decided to make the shop bigger, so I went with a 60x60 shop. Needless to say I will not be invited to any neighborhood parties thrown by 2 of the 3 approval members anytime soon..