Ya gotta love these SpaceX guys...
SpaceX is trying to make a difference here. They certainly have stuck their necks out to even get a chance to succeed. Constraining the manned-mission work to the Shuttle for 30 years really stunted the progress of American technology. The USA was left with a single capability to do LEO manned-work and that capability was poorly scaled and poorly adapted to current cost structures.
SpaceX had taken what-works-for-cheap (RP1 petrol-rockets) and adapted it to what-works-for-cheap manned-transports (Dragon capsules like Soyuz/Apollo). They will take a run at getting it into LEO and do-no-damage in getting it to the ISS docking-arm.
There is less high-cost automation for the docking mechanism than Soviet-Progress. There is lower-cost associated with survivable return (vs. Soyuz). It just needs to work.
Orbital is also in this business and have had a few launch failures with their Antares lifter. They may be able to replicate this expectation within 6-8 months. We will see.
There has been a lot of talk about very-advanced next steps (exhausted rockets flying/landing for reuse) and even $500K Mars trips within a decade. God bless all of that stuff...
This is what is fun about manned space flight. Now, they just have to pull it off!