Flying in IMC in a kit aircraft or without a rating to do so is not illegal, or at least it is only illegal if you do so intentionally.
If you find yourself in a situation when you have no other choice it may be the only option so it is no bad thing to have the kit and the training to do so safely. I'd not fly a kit aircraft unless I knew I had the basic equipment to cope with an unexpected incursion into IMC, and any pilot I taught to fly I would expect to be able to do a basic job on instruments.