A kiwi perspective from someone who's still a relatively junior instructor (700 TT) -
I am a product of a so called "sausage factory" at Ardmore, first as a student and then for a year-and-a-bit as an instructor. The company policy re: low timers was "You can work for us if you bring your own students", and they had virtually no quality control for new instructors. I got through my 100 hour "direct supervision" period without having so much as seen a senior instructor in the briefing room let alone take an interest in my flying. While I didn't feel "unsafe" I definitely wished at times for a bit of guidance, certainly the student is the long term loser in that situation.
It's worth noting that the senior instructors in that place were if anything worse than the young ones (who at least were keen): the old timers were in my opinion a bunch of demoralised, cynical pricks who didn't want to be there and it very much showed up in their training standards ...
However, since August last year I've left Auckland, and been working for a small, tightly run, happy organisation in a smaller town with an active airline pilot (Air NZ Saab 340) running the show, and it has been an absolute mind blower for me. I feel like I have learned to fly and instruct all over again ...
The conclusion I have drawn, is that sausage factories by their very nature train to the lowest common denominator. They are very hot on standardisation, which is all well and good and it's obviously the way to go when you have to fly with a variety of different instructors none of whom really get to know the individual strengths and weaknesses of their student. But it can't touch the benefits of true "one on one" training with someone who really knows what they're about and takes an interest in their student.
While there is no substitute for experience, I feel a low time instructor in the right situation can be a fine instructor, as long as someone with experience is looking after them and paying more than lip service to "instructor supervision". And a high time instructor who doesn't want to be there, is about the worst thing a student can have ...