Putting it in terms that some of you may understand, think of the EU as UKA and the UK as the FRA.

When the FRA joined UKA it was a tough decision. Ultimately, whilst the FRA still has a great deal of influence, the ultimate responsibility is with UKA.
UKA make all the rules, and whilst the FRA has influence on them, so do all the other "interested parties" and sometimes something may be put in place that doesn't best suit the interests of fell running, or an aspect of fell running.

The linkage to UKA is still an issue for some members of the FRA. There are costs and benefits.

I'd say with the EU, that the costs have eventually been deemed to outweigh the benefits.