Keep in mind that physical therapy, much like chiro, has no real proven medical value in the mind of many allopathic docs. The culture of allo medicine is now evidence based treatment decisions (surgery X vs surgery Y measured success rate, medication A vs B proven results, etc). For manipulations, it's all subjective: the patient "feels better," "seems to be getting more motion," "feels a tad bit less pain," etc. The stretching, range of motion, etc is really nothing all too different from what rehab or long term care nursing assistants, personal trainers, etc will do for clients. Sure, there are physical therapy modalities that theoretically improve local bloodflow temporarily (baths, massage, ultrasound) or increase flexibility (stretching and ROM), but the results are all relatively subjective. The only stuff that PT can really do that has proven medical value is iontophoresis (sending dermatologic creams down into the tissues with ultrasound or electric current), and they need the referring doc to write the Rx for those creams.
Some pods I've seen have their patients do a lot of PT during surgical rehab, and others don't use PT for much aside from gait training their hospital inpatients (walker, crutches, scooter, etc). PT isn't very well covered by most insurances unless it's rehab for a major injury (auto accident, workers comp, stroke, etc). Weeks and months of sessions will burn a lot of cash very fast, and the pod or ortho patients can often get more bang for their healthcare buck using that money differently (imaging, surgery, medications, braces, orthotics, etc).
A lot of ortho and pod docs that I've seen will send the patient to PT for a just few sessions after removing a case/brace. The patients need to get some flexibility back, and the idea of sending them there is that they will learn some stretches and motions that they can do. Some docs will send them there for months and months... but usually only if the patient has great insurance and/or they don't think the patient will commit to the stretching and strengthing on their own. PT becomes basically a high priced personal trainer, stretching coach, or massage artist for those patients.
I'm not bashing PT here, but you just have to realize what it is and its limitations. Podiatry is an evidence based specialty, and we have objective data for most of the stuff we do. Sure, there is anecdotal evidence and personal experience will always have a role, but I don't think very many pods twist knees, pull on heels, or crack toe joints to cure ailments if that's what you are asking. You can't fix a bunion, fracture, or flatfoot with your bare hands... unless maybe your nickname is "JC"? Any "alignments" or "adjustments" that DPMs do are generally achieved with surgical manipulation of bones and tendons, braces/shoes/orthoics to limit motion, or both.