Another reason people draw in Stud is that they are usually getting the odds
to do it.
"They also keep chasing to the end when they have any straight draw, open or gutshot, flush draw, pair, 2 pair when its obvious they need a miracle."
Take an example where we are playing .50/$1, I have an open ended straight draw (8 outs). Say none of my 8 outs have been exposed. Say there are 3 people in the hand and we are on 6th street. You have a pair of Kings exposed and most likely have 2 pair since you've been betting since 4th and just made your Kings. Let's say we started with a full table.
We've seen 17 exposed cards at this point. My 4, your 4, the other guys' 4, plus one each for the other 5 players that folded on 3rd street. So it's 8/35 = almost 23% to hit the straight.
.05 ante * 8 = .40
3 players call .25 = .75
3 players call .25 on 4th = .75
3 players call .50 on 5th = 1.50
2 players call .50 on 6th = 1.00 action is on me with the straight draw...there is 4.40 in the pot and it's .50 for a call. I have the odds to make this call even though I'm obviously behind.
7th street, I make my straight. You lead out with your 2 pair because my straight is hidden, other guy folds, I reraise, you call. I win a nice pot.