It's the nature of the beast in Division I football right now. QBs all over the country are transferring left and right if they aren't the starter. I don't like the trend, but we can't pretend that this is a problem that is limited to Ruston. LSU lost its third and fourth QBs during fall camp.
Just look at what has happened at Georgia. The Bulldogs started a freshman, Jacob Eason, in 2016. He got hurt in 2017 and was replaced by another freshman, Jake Fromm. Eason transferred to Washington is likely the starter next year to replace Jake Browning. Georgia brought in another highly-touted QB, Justin Fields, who has played as Fromm's backup QB this year. It will be interested to see that situation play out and if one of them ends up transferring during the offseason.
I hate losing guys, especially a guy like Abraham who didn't stick around long enough to even compete for the job, but it's not an isolated problem and it's not anything that Skip Holtz is doing wrong. There are backup QBs all across the country who believe they should be starting, and they're looking toward greener pastures to get that opportunity.