Generally electrical Co-ops are not owned by corporations, many were created to fill in the rural gaps that profit making firms decided it was not worth filling. Many go back to the REA days. In most cases they have elected boards elected by the rate payers. Few folks really care about how the power gets to them so some Co-ops are run by small self serving managements that have "rubber stamp" boards. They are going to do what is easiest way to run the utility and keep their jobs. Others are quite progressive, there is large one in NH, NH Electric Cooperative that is always putting "Neversource" to shame for RE initiatives. Eversource is a behemoth and really too large to regulate on a state basis. Coops tend to be non profits and due to their rural nature, the net return on investments is low and they tend to keep what they got running versus upgrading to new tech. Most older power systems were strictly one way distribution, once distributed generation like PV appears, it gets complex and costly quick to meet the technical standards to ensure that the distributed generation does not impact other customers. Interconnection departments required to review and determine system impact are tough to staff as there are very few folks with the background and skills to do the work, there are only a couple of universities that even have bulk electrical power programs and even a graduate of a program required decades to get good at it.
The result is many small Co-op run by long term conservative management supported by passive boards, just adopt the approach to try to delay the inevitable and push upgrades to some future management. I was working with one small Co-op whose staff consisted of a couple of bucket trucks with linesmen, a working linesman foreman, a billing department and manager/engineer. Even with such a small staff, the Co-op members were quite progressive and at one point they installed a landfill gas generation system, long before they became popular. The staff were all long term and liked working with each other and I expect they all could make more money elsewhere. They were quite RE friendly as the board and members supporting the expense to upgrade their systems for some DG.
The other thing to consider is in most cases small Co-ops are not regulated to the same standards that large corporations and even large Co-ops are held to. Generally, PUCs can dictate the big boys to follow state rules but many small co-ops are exempt.
As someone who used to try to install industrial Combined Heat and Power systems that needed to be able to export the grid, I know we had a few projects that made sense for the business but were sidelined by the local small Co-op who always had bought power from the same firms and had no interest in local generation. In at least one case, this kept the local firm from upgrading and expanding their operations which would have hired more people. I also went through several real full out system impact studies at a circuit level and they were extremely frustrating and expensive. Long ago there were large projects that got added to the regional grid that caused substantial impacts and required expensive upgrades and after several of those, FERC ruled that anyone trying to connect to the grid has to pay for the improvements required by the project as determined by system impact study. In most cases the local distribution stations feeding the plant circuits were 1920s vintage. They were connected to the regional grid by copper T-1 lines. Phone companies do not want their copper in electrical substation and required very specialized protections. When we needed to upgrade a circuit in that substation, if it had copper communications, the clients got to pay to upgrade to fiber and install a new comms panel . Utility grade gear is not cheap, figure 300K to swap from copper to fiber and 12 to 18 months of getting the phone company to play with the power company on the client's dime. Most of those substations were set up for power to flow only one way so something called a 3VO upgrade would have to be done to upgrade the equipment for two way power. That could be a 800K upgrade. In several cases, we had to compromise the project as the client could not afford the grid upgrade cost so we put zero export relays in the switch gear to just not export.
Most states have passed rules requiring utilities to have "short form" interconnects for small projects that in theory will not impact the system these depend on grid tied inverters with UL 1471 certifications to drop out the local generation when the local grid is in trouble. Unfortunatley the "guinea pig" for high PV penetration, Hawaii learned that too much snall PV ads up on their system and made it seriously unstable and took several years and major upgrades to get it to work. Hawaii didnt have a choice they mandated the upgrades needed to ge tth system to work but a local co-op is probably out of luck and not covered by state rules so the easy way is to just make it tough. If folks in a Co-op do not like it, it's time for them to see what it takes to get elected to the board. If enough people do, then they can change the local policies but be aware PV has become a hot topic for MAGA folks who oppose renewable because their leader has told them so. The Koch brothers sponsor ALEC and ALEC work down to state, regional and even local level to quash RE legislation and those who support it, so do not be surprised if a local Co-op board election suddenly becomes lopsided where one party is getting checks and support from a national operation.