As a factual matter, the filibuster was totally unintentional and the result of a snafu during an editing of Senate rules back in the day. But its been around a long time... then again, for most of history it wasn't abused like Democrats try now.
The fillibuster used to be impossible to end (only the Senator fillibustering could end it). However, it's been made easier to end via Senate rule changes. Cloture on a Senate rule change is a 2/3rds vote. That's 2/3rds of those voting. Yet, Republicans don't want to follow the Senate rule change procedure. If only 27 Democrats showed up one day, the Republicans could legally change the rules, but they'd rather break the rules.
