Is Craigslist broken?

My experience with Craigslist these days, is firstly people asking you if the item is still for sale.
Then when i reply that it is, I'm then told i will be around your city visiting family, friend, or doing business.
Is it ok to come and pick it up?
Then when replying again, and say yes, of course, they never again make any more contact with me.
Why do they do this in the first place, if they don't have any intentions in purchasing if from the get go?
This has been happening more and more lately, with my ads on the local Craigslist. (Sacramento)