Depends a lot on how much you expect friendship to mean. I'm entirely open to new online friends, because they take hardly any effort on my part. But real-life friendships demand a lot more time. And when I can't keep up with the demands of existing friendships, it seems wrong to start hanging out with new people.

That certainly happened when I was living in London -- I had a full-time job and a relative I was caring for, so had very limited time to interact with even my closest friends.

But I've also been on the other side very often -- especially in the position of having moved to a new town and feeling very alone. Sucks to be there!