Yes, I don't disagree with that response. It was unclear from the your bold assertion "DO NOT" as to why they should not.
I would certainly be the first person in the queue advocating careful research and taking a measured approach.
Interestingly, the majority of people who are on cadet programmes do not already have a PPL. Very few, if any, seem to decide they hate it once on a programme. Those that are subscribed, regard it as a "graduate" apprenticeship to an airline career. Indeed, that is what it is intended to be.
Too many people seem to labour under the illusion that a 250 hour CPL/IR, outside of one of these schemes, is simply a cheaper way to exactly the same thing. That being a cadet airline career with 250 hours. It isn't, and no amount of wishful thinking will make it so.
If asked the question, "what is the best chance for an airline career for a new 200 hour pilot?" The only honest answer I could give is through one of these affiliated cadet schemes. They are intensive and expensive. However they are the fast track programmes that might satisfy that goal." If I were to answer that same question by stating "Find the cheapest modular route available. Get your licence, IR, and 250 hours and then go knocking on airlines doors." I would be lying. Recruitment isn't, and never has been through this resource at this level of experience.
I don't mind if people think otherwise, or highlight the exception that they believe proves the rule, but it simply wouldn't be honest advice on my part.
For somebody embarking on arline flying as a career, they would most certainly have to consider this path. For a fast track career, it is pretty much the only game in town. Not everybody will be successful, and certainly few will be able to afford the investment risk. There are alternatives, that are cheaper, not at all "fast track", and littered with far more corpses, but the realities need to be understood.
It is therefore bad advice to tell somebody "DO NOT" sign up to one of these programmes without qualification, anymore than it would be to tell somebody "DO" sign up to one of them.
Hence my question...Why?