When ambiguity is ambiguous

I am always fascinated by cases where the courts can't agree whether a contract is ambiguous or not. The very fact of there being disagreement should probably point to the contract being ambiguous, right? A recent case out of Pennsylvania, SBA Towers II LLC v. Wireless Holdings, LLC, No. 325 WDA 2018, gives us another example. The lower court and the majority on appeal found that the clause in question was ambiguous. A partial concurrence/dissent, however, would have held that the contract was unambiguous. The dissent argued that the majority was finding ambiguity in the contract's silence, and that in this case ambiguity should have been rooted in something about the contract itself:

"In sum, although an ambiguity could, in another scenario, arise from the silence in a contract as to a particular term, Appellees in this case have failed to articulate a basis for finding ambiguity in Paragraph 18 of the lease, e.g., unclear wording or punctuation, the impossibility of enforcement of the contract term as written, or language in another paragraph that would make Paragraph 18 confusing or unworkable."

The majority opinion is here, the partial concurrence/dissent is here.