I play alone probably 75% of the time, and I love it. Around here, the golf courses (usually) aren’t very busy, and I can get around in under 3 hours. And, since the courses are so empty, it is a quiet peaceful environment. For me, there is nothing more therapeutic than spending hours outside alone. As @ZenGolfer said, it can be a meditative experience, and a calming escape from daily life.
On the days courses are busier, since I can’t play a quick round, I love being paired up with people. Meeting new, interesting people is always fun.
Basically, in case you can’t tell, I like golf.