I would say that friendship is very important, especially the right friendships. I have a few close friends that I can count on my fingers and these friends are always there for me. I'd much rather have few friends than be surrounded by people who don't really care about me and people who I just mix with because we happen to work together, but we aren't really "friends".
I don't really bother making friends at work either as most people I work with are fake and up themselves and not the kind of people who would bother to keep in touch. I wouldn't say no to making friends at work, but I don't actively seek friendship from work. I prefer to keep myself to myself and do what I'm good at. Unfortunately that work place can be like school and there's a lot of gossiping and backstabbing.
You're better off making friends by joining a club or group of interest. For example if you want to learn a language why not enrol to a language class or group or if you for example like theatre or art, join a theatre or art group. Or if you belong to a religion or ethnic or cultural group, you could join a group to do with that. You're more likely to make friends with like minded people who share similar interests and values. Also chose to befriend people who have similar values and interests such as yourself. For me good qualities in a friend are similar to mine; strong family values, respect for others, being caring and genuine. I don't like people who gossip about others.
Friendship is important as a life without friends is lonely and sad. However quality is more important than quantity. It's better to be surrounded by a few good people who genuinely care about you than loads of fake friends who only want to hang out on their terms and don't take an active interest in your life. Hope this helps!