I see it's time for another round of "I got nothing else, so I'll play the Southwest PFT card again!"
Why do you keep harping on this? Seriously? Different airlines have different minimums. For SWA, it's ATP, 737 type, and 1500 turbine PIC hours. Other airlines require less hours, or no type, or not even ATP. It's up to them to decide what they want, and up to you to get it if you want to apply there. SWA doesn't require a 4-year college degree; others do. Why don't you give grief to Delta for requiring a college degree of their applicants when we don't? Why don't you give grief to airlines requiring ATP when some others don't? Clearly this is just the piddly-crap you've come up with to bash SWA. 'Cause you don't like our minimums? If that's all you've got, then I feel pretty good about my choice of employer.
Why does SWA still require it? I don't know for sure. In the beginning, I suppose it was to make sure that you really wanted to work here (a new airline) and weren't as likely to bolt after training and stuff. Nowadays, while clearly they could probably do without, it still ensures that SWA attracts applicants who really want to be here. Plus, this way, they know you're qualified to be a captain when you start; fewer surprises later. Also, since they know you're qualified on the only airplane we've got, that allows the interviewers to concentrate on finding out about your personality, and whether they want to sit next to this guy for hours at a time.
To answer your other question about the six-month thing, and if they "fire you" if you dont' get the type rating by then. You actually only get "provisionally hired," without the type if you pass the interview, but you can't start newhire training until you get the type rating within six months (that is, finish satisfying the company's hiring minimums).
Well, there you go--answers to your questions. Although I suspect you really weren't looking for real answers--you just want to bitch about Southwest. However, it really is as simple as Scoreboard says: if you don't meet the minimums for any job position (whether that be so many hours, an unrelated college degree, or whatever rating or ratings), then you can't apply. If you wanna' bitch, then knock yourself out. However, you'd be better off utilizing your time applying to a company whose minimums you DO meet, or work to increase your personal qualifications. Your choice.
Bubba