I was on my own in LotR until about level 35. I had some friends start the game with me, but they dropped off in the first month. Then I had a lonely kinship where I was the only guy active for close to a year. That worked for me because I played the game off and on. I slowly made it to my 30's doing lots of solo quests, playing alts, and very rarely grouping. I think I went 6 months without being in a group. Then, in my mid 30's, I met someone I liked and joined their kin. It was active, and the last few months have been moving very quickly, and I've started to learn hoe to play in a group well. My class, Captain, has a lot of great buffs and a few small heals, but is still very active in the attack.
But I did enjoy playing the game as a solo experience. I never felt bogged down, and the world was interesting enough to keep me engaged. There are also quite a few different areas to travel and level up around.
edit: It helped that the game is only $10 a month, compared to the $15 of other games. I found that a bit easier to stomach.