Oh I completely agree that 45 degree turns in a high wing aircraft on a sight seeing flight is not necessary (wing might block the sight, less comfortable for pax etc etc). The handful of times I have performed one in this circumstance was more so the passengers could experience a G or 2 as opposed to performing the turn for the purpose of viewing sights on the ground.
In hindsight if I knew my original comment about the 45 degree turn was going to be the focus of replies then I would have said a 30 degree turn just as an example of how an increase in power would be needed to perform the turn if going from slow flight re: juggling the throttle & pitch lever.