I found this to be curious...
I didn't, it's a standard and well established part of the political process Mike - what makes it so curious?
Reid wants the necessary three-fifths (60) votes to allow a motion for cloture to be presented if an attempt to filibuster is made. It doesn't stop the debate it sets a limit on the amount of time a bill can be held up if the majority believe that the bill deserves to be voted on.
Whenever points are brought up that makes Reid or the Democrats uncomfortable he can simply call for a vote to end the discussion
Actually it isn't that simple Mike, and it certainly doesn't end the discussion as abruptly as you suggest.
If he can get 16 Senators to sign a petition for cloture Reid can interrupt any speech to present the petition. The petition is read out and then put aside and the debate continues for up to 30 hours. The next day a quorum is called and the Senators vote on the cloture motion, which requires a minimum three-fifths (60 vote) majority.