For the most part, you're right - you really shouldn't do any harm with dropping the steaks in when the bath is pre-heating.
That being said, there's a reason that ANova named their sous vide water circulator the "Precision Cooker" - one of the attractions about having a sous vide appliance is being able to reproduce the same results time after time.
Putting your 1 1/2" rib steaks in for 90 minutes and having X result is desirable - not only from knowing what that is, but being able to tweak it next time increasing / decreasing the cook time (and possibly the temperature) to create a different result.
If you're not precise about your controls, you won't be precise with the result. Just saying - you can set the bar higher - as in as high as the best steak houses in NYC and produce similar results.
If you really want to make the best steak you've ever had, might be good to start a journal and keep track of your experiments.