So your comment implies flying an aircraft that needs to be trimmed and with manual thrust is dangerous. Quick - Ground all Boeings!!
The issue people are trying to get at is that when you drop you're already in a higher than normal pressure situation and now flying a new beast. It can not be helpful considering all the details changes one must now deal with cognitively as opposed to autonomously. Take for example someone who ended up constantly pulling back on a stick which would have different results in each mode.