I think you are adressing here a false problem. I came to Aikido from a Judo background. In the beginning, I was proud of my Judo skills. Aikido locks were not effective on me (when done by my fellow beginners). I was taking pleasure in immobilizing every one at the dojo down Judo style. Once one of the senseis saw me bragging about my immobilization skills and asked me to pin him. When I did, he just grabbed my testicules strongly and I had to let go screaming with pain. He pointed out to me that Judo is a sport, and has rules. In the real life situations there are no such rules. Aikido locks might not be very effective, especially in the beginning, but they are very safe against any potential attack from your agressor. In case the pin fails, you just step back one or 2 steps and you're ready to defend yourself again.
However, I can assure you that pins by my sensei are so painful that I wouldn't even try to breath, let alone resist, when they are applied