That decision usually rests with the department making the decision.
There are many reasons why you could choose a non-competitive contract. They're allowed in the procurement policies and directives, but when that happens, you would expect that you would have clearly documented your interactions with the vendor and that you would have also documented clearly why you chose them.
Typically, to go non-competitive, there needs to be a really good, valid reason. In this case, there was very little documentation as to why GC Strategies was selected and how they could fulfill the requirements of the contract.