I was only 12 at the time, but I didn’t even know until last year that Gore won Florida. All I remember is hanging chads, recounts, but nothing about Gore being the rightful winner. From a child’s perspective, it must have been swept under the rug because I remember nothing about it and don’t recall anyone harking back to this issue even in the years that followed. Why?
I don't suppose anyone can answer why it's not a 'bigger issue', but we can certainly shed some more light on the circumstances. The biggest issue the Florida recount ran into was the timeline. In a presidential election, there's a window between when the election itself is held (the Tuesday after the first Monday in November) which in 2000 was November 7, and when the states are required to certify their results (the 'safe harbor' date) which in 2000 was December 12. That gives roughly a month to complete the process and settle any issues before the state presents their electors.
The Florida Secretary of State called the election for Bush on November 8, after the count ran into the night on election day. The Florida Supreme Court ordered a recount beginning on December 8, just four days before the safe harbor date, which was appealed up to the Supreme Court immediately.
The Supreme Court halted the recount, with the majority ruling stating "Because it is evident that any recount seeking to meet 3 U. S. C.§5's December 12 "safe-harbor" date would be unconstitutional under the Equal Protection Clause, the Florida Supreme Court's judgment ordering manual recounts is reversed.”
The Equal Protection Clause in this case refers to the state's responsibility to ensure that the manual recount across the entire state was handled in the same way. In other words, the Court ruled that Florida did not have an equitable system in place to manually recount the votes, and they wouldn’t be able to create one in the four days remaining before the election was certified.
Controversial? Certainly, and to this day. But in keeping with the electoral timeline and the Supreme Court’s ruling, the plaintiffs were quite simply out of time.
Bush v. Gore, 531 U.S. 98 (2000)
EDIT for clarity: Technically December 18 is when the states have to certify their results, but according to 3 US Code 5, they have to determine how to handle any controversies six days before that date, which is where we get December 12 as the safe harbor date