Firstly, not many fields in the US allow full auto, even though it isn't illegal, for insurance reasons.
Secondly, enabling the tournament lock (by removing the grip and flipping the dip switch; since I don't have a storm I can't be more specific) is probably good enough for most field owners, although not adequate for UK law. In fact, a frame sufficiently crippled to meet UK requirements should be difficult enough to return to full functionality that it's not worth considering.
So you either have to permanently disable full auto (by setting the tournament lock then aralditing the switch in place, for instance), or risk getting arrested for having a full-auto capable firearm, even if it is temporarily disabled. Your call.
And I don't think people specifically don't like full auto here, except that (a) people see it as a pointless frill, and (b) a lot of people are very conscious of the image of paintball in the eyes of the law, and are anxious to avoid an image-damaging criminal charge cropping up.