How much do triathlete need to learn about swimming?

I do not mean this as a heartless criticism of triathletes. I actually enjoy the sport. But many of them start doing triathlons with almost no knowledge or experience in swimming. Here are a couple of choice comments to the thread I linked below. Thank goodness I knew how to ride a bike and run before I started doing tris - but not well. Give them credit for taking it on, but I do think they should learn to swim before entering one. "The swim is short ( 150 yards ), and I can make it..not without stopping a couple of times at the end of the pool." "A lot of pool sprints are so newbie friendly that they let you get through the water any way you can. I have seen people water walk the 300 meters in a pool swim in my area." "My wife did an indoor tri a few months ago and I think 1/4 of the people walked the swim." I recommended that the person do breaststroke. www.beginnertriathlete.com/.../thread-view.asp