Because this is where the cloture procedure come into existence.
Both sides come up with this lipsticked pig rule change, I believe in the 1950's or 60's, so they wouldn't have to get off their lazy ass and actually hold the floor.
This way they didn't have to do without sleep,the parties, weekends off, interfere with spending our money and all members of both sides having to stay in the building and on the job when it was broken and a vote promptly called.
In other words they changed the rules to make it more convenient.
Can you see any of these fat cat over aged alcoholics standing on the floor away from the good life for very long.
So they made it convenient. The end result was this mess.
Under the old rule when they filibustered Bolton Thursday then some democrat would have had to take the floor and started talking and he would have still been talking now and right on through the weekend or until he collapsed or yielded.
The rest would have had to stay in the building because as soon as he did the vote would have taken place.No long Memorial Day weekend.
The filibuster was never intended to stop a vote only to delay it as long as an individual could stand and physically hold the floor.
They changed it to where a if a certain number of senators, I believe 17, agreed in written form to filibuster that the subject of it was considered filibustered permanently or until you could get a super majority of vote in this case 60 to break it.
They took what was a delay tactic and turned it into a veto.
I believe this rule change would be declared unconstitutional if properly argued before the courts.
The rest would have had to stay in the building because as soon as he did the vote would have taken place.
I think the barrier to scheduling a vote is that it takes unanimous consent to schedule a vote. It doesn't have anything to do with holding the floor.
Under your rule, some GOP Senator could take the floor, hold it until he drops, then WHAMMO! Vote!
In all the "hold the floor and talk" filibusters, the person on the floor was there voluntarily. Wasting time served their cause.
No doubt, Senators have held the floor to advantage, but I don't think there was ever a rule that a proponent could wield, that would force the opponent to take to the floor if the opponent doesn't want the floor. I've looked for it, and haven't found it yet ;-)