I'll help the others see what you refuse to acknowledge.
The legality of Cruz's name being on the ballot is a state law issue. Your argument was that federal courts would not reach the merits, and would instead dismiss the suits on procedural grounds, such as ripeness, judiciability, or some other rationale that resembles those. Being dismissed in federal courts, while an interesting academic exercise, does not resolve how state courts might rule, nor does it address the existence (or not) of state laws that bear on putting the names of ineligible candidates on the state ballots.
In short, the argument is on whether a case lies in any court, which is state court in the first place, and your response is that no case lies in a federal court.
I encourage Donald Trump or indeed anyone who wants to try, take this to whatever state authority you are advisd has jurisdiction, and make a serious and sincere effort to have this adjudicated. I doubt you will get a favorable result.