I never heard of such a explanation unless these guy's have no clue about flow coating an interior !!! Don't give up, get another opinion !!! B&K Boat Repair can do it Eliminator can direct you to someone too. It's too clean a boat to just give up on it. All a flow coat is is spraying in a coat of resin with a surface agent in it so it will harden then buffing it out. You need to sand the interior completely prior in order to get good adhesion. That's probably why they are balking at it. Too much work. A bit of sweat equity on your part should really get the price down. The rotten economy should help too, even good shops are finding work hard to come by and will be lowering prices.