As someone who has spent many, many hours photographing alone, I love to go shooting from time to time with other people. Sure it can have its distractions, but I also find the conversation can be very stimulating when there is someone around that does what I do. It is not as if you are attached at the hip either. As long as you respect the other photographer's space and they respect yours, what's the problem? Just set your boundaries ahead of time and no one gets hurt.