The biggest barrier by far for this market is the status-quo: if you have to add even a few steps to employees’ current workflow, the project will have a much harder time getting off the ground.
Hasn't this sort of thing been in production for years with UPS/WalMart/etc?
Also, RFID as a commercialized technology is still relatively new (even though it's been around for a long time), and there are a lot of technical hurdles that most people don’t know about. For example, a standard, Wal-Mart style RFID tag won't read if you hold it close to the body (or put it in a pocket), or put it on metal or liquid; in those cases, you have to use a special tag, or a battery assisted tag ("active rfid", which can be much more expensive), or an "RTLS" tag (wifi, ultra-wideband, etc). It's all really interesting (to me anyway), but the industry has had to spend quite a bit of time getting over all of the hurdles that are non-obvious (like any industry I suppose).