I have some sick masochist quality about me where I NEED to beat bosses solo. In fact, I have never summoned another player in all my Souls playtime for any reason.
I wonder if anyone else here has the same hang-up.
I'm with you, big part of these games for me is the process of learning a boss and finally pulling through in the end, I would lose all that with summons. I save summoning and co-op fun for later playthroughs.