> Regardless, pouring boiling water out of a kettle is far less dangerous than pouring the cooked pasta + boiling water out of the pot and into a strainer.

I don't think this is true. The mechanics are essentially the same. But the colander receiving the pasta + boiling water is situated inside the sink, which will catch the water that is in that case intended to spill out.

The pot is situated on the stove, which is a raised platform that can't catch water at all. Any spill there will splash all over.