They have not left anything unresolved. They have made it clear they expect every other court to follow suit and legalize homosexual marriage. Unhappily, this has been the result of 50+ years of viewing marriage as being about adult happiness rather than building the next generation and a societal interest in stable families raising kids with effective role models.
But if anyone had opposed easy divorce laws in the 60s based on the idea that a slippery slope had been created that would allow homosexuals marriage to be endorsed by the US government, they would have been laughed at!
Exactly.