I've had a few friends get hired at mainline without any TPIC. The most recent was a ASA to JetBlue buddy. Two went to CAL in 2005 with zero TPIC from ACA. One to Virgin just recently (had twin otter PIC) from Republic.
And that's just in my little world. So there's definitely more out there. Not to mention, all these people are white males. So they had that "disadvantage." I'm sure when retirements start cranking, seeing guys interviewing/getting hired without TPIC won't be as unusual as it is now.
I think the only airlines to actually require TPIC are SWA, FedEx, UPS and Alaska if I'm not mistaken?