Suddenly reacting and doing something that should have been done earlier without reassessing the current state of affairs can cause even worse problems.
For example: forgetting to retract the landing after take off, suddenly realising it and operating the lever at a speed in excess of VLO could damage the gear doors. Assuming VLE hadn’t been exceeded, slowing down to the correct speed before retraction would be the correct course of action.
Levelling off if at a suitable altitude and attempting to pressurise with a single bleed source, pack flow low and a selecting a reduced cabin V/S would avoid a sudden thump of pressure. Obviously a higher altitude would require descent rather than a level off.
Unfortunately we as human beings often have a knee jerk reaction without thinking first.