I don't really buy that this is the main reason. A good senior engineer is for the most part able to not write bad code from day one, just at a very low speed and with the need to ask other people frequenyly. Even if you do not know the code base or domain yet there are a lot of things you can do to avoid writing bad code. Yes, as someone new you will make mistakes and misunderstand things but a lot of the bad code I have personally seen has not been caused by that. Most bad code I have seen has been caused by people rushing and not having their fundamentals in order. Like not actually doing reviews, not spending a few extra hours to think about architecture, etc. Also a big issue is that people just let the complexity of systems explode for the gain of short term projects.
I think the issue is more that engineers face unreasonable pressure to deliver short term value and that there is no respect for the craft/engineering from many managers or even engineers.
I think the issue is more that engineers face unreasonable pressure to deliver short term value and that there is no respect for the craft/engineering from many managers or even engineers.