What is the "1992 Crimean constitution"?
How is that different from leaving things unchanged?
In 1992, being at odds with national powers, Crimean leaders declared the independence of the peninsula and passed a constitution that proclaimed Crimea to be a republic within Ukraine, provided that Crimean laws would have priority over Ukrainian laws, established Russian as the official language of the territory, and allowed Crimea to conduct its own foreign policy. Following a series of compromises with national Ukrainian authorities, this constitution was repealed, and the Verkhovna Rada (parliament) of Ukraine granted Crimea the status of an autonomous republic within Ukraine and adopted a separate law which defines the jurisdiction of the Crimean authorities. The law allows Crimea to pass its own normative acts provided they do not contradict the laws of Ukraine; adopt a budget and impose local taxes in accordance with the Ukrainian national tax system; implement its own policies in the fields of environmental regulation, social protection, culture, and humanities; and conduct local referendums on questions included in the republic’s jurisdiction.
Crimean History, Status, and Referendum | In Custodia Legis: Law Librarians of Congress
P.S. Crimeans DID NOT want to leave the things unchanged, they have had huge protests against the coup.
So the two choices were leave Ukraine and become part of Russia or be independent.
Why not, "be part of Russia or leave things unchanged"?