That makes no sense. If you can mine on a pool, you should be able to solo mine. Whether it makes sense to solo mine is a different question.
You're right, this sonds like it could be a case of a miner who doesn't want other people
getting into mining it so they have a higher chance of finding blocks. Pretty much the only
thing I've heard about Gold is that you'll be able to GPU-mine it, though admittedly I haven't
looked into it at all.