According to https://en.wikipedia.org/wiki/Standing_(law) the requirements for standing were developed in the Constitution and elaborated in some later cases. To quote from the article, the apt criteria seem to me (2 of the 3):

1. Injury-in-fact: The plaintiff must have suffered or imminently will suffer injury—an invasion of a legally protected interest that is (a) concrete and particularized, and (b) actual or imminent (that is, neither conjectural nor hypothetical; not abstract).[44][45] The injury can be either economic, non-economic, or both.

2. Causation: There must be a causal connection between the injury and the conduct complained of, so that the injury is fairly traceable to the challenged action of the defendant and not the result of the independent action of some third party who is not before the court.[46] ---

The best way to understand why standing was not found is to read the court's ruling. Unfortunately (but not unusually) 404Media has not linked to the judgement. (I will try to find it.) My guess (IANAL) is the injury is hypothetical or conjectural.

Update: this is the most up-to-date info I could find: Case 15-25-00202-CV

https://search.txcourts.gov/Case.aspx?cn=15-25-00202-CV&coa=...

Pamela Griffin, Ralph Griffin, Michelle Griffin, Corey Griffin, Individually and as Trustee of The Griffin Revocable Living Trust, and Polly Randle

v.

NCP Travis TPP Project, LLC

But the records only go up to February 20th.

There was an interesting case Knife Rights v Garland (v1) where they determined you also don't have standing for imminent jeopardy if no one has done the imminent thing in decades in a way that results in criminal rather than just mere economic damages. This is why those in danger of getting a felony for interstate commerce of switchblades are unable to challenge the law because it's not considered an injury to merely have your business destroyed and your inventory seized.