Hmmm. I think people gave you the kind of answer they usually give to nursing students looking to work in an ICU. The truth is a little more complicated.
Having trained a few dozen ICU nurses over the years, I'd say on average that nurses with med surg or ED experience are easier to train than new grads and become competent and independent noticeably quicker. Of course, individual differences apply, but on the whole it's not even a particularly close race. And I'd even go so far as to say that most people who genuinely understand ICU nursing would readily agree with me on this (note that not every ICU director actually understands the ICU, and certainly not every HR rep hiring for ICUs does).
The whole bad habit line has an element of truth to it - a bigger element once we start talking about experience in specialties that have very little skill overlap with ICU nursing. But it's overstated, and doesn't really apply well to med-surg, step-down, PACU, or ED. If it did, new grads would need shorter orientations than nurses with other acute care experience; in the real world, the opposite is far more commonly true.
However, you're certainly right that some places seem to prefer to hire new grads. There are reasons for this, but not the ones you gave:
- Hospitals, in their infinite wisdom, have mostly abandoned the concept of merit pay or paying for relevent experiece, and almost across the board now pay nurses a scale based on total years of experience. That means that an ICU pays a nurse with 20 years pf ICU experience more or less the exact same wage as a brand new ICU nurse with 20 years of experience working in a doctor's office. So in theory, that means once you put your time in in the nursing profession, you don't need to take a pay cut to change fields. In practice however, it actually means that it's harder to switch fields at all after a while because managers don't necessarily love paying for experience that was not in the specialty they're recruiting for. New grads are cheaper.
- Many hospitals especially like hiring new grads into desirable positions because they can then leverage new grads into signing contracts requiring them to stay for 2 years or so or else have to "pay back" $10K or so for the costs of theor training. This is better than indentured servitude, but not much, and it can make new nurses feel compelled to put up with some real BS. Which is, of course, the point. It's a way to enforce retention.
- Hospitals that are worried about nursing staff pushing back against hospital administration or about the threat of unionization often find it advantageous to keep themselves staffed with a revolving supply of people new to the field.