There is nothing more wrong with an S turn on finals than a sideslip. All you are doing is increasing your track distance to touchdown and hence increasing your spacing to the aircraft in front.
Both require a certain amount of minimal skill the S turn with less danger as your glideslope remains the same as does the rate of descent as equally does your speed.
Generally I agree with you Pace. However I would consider a S turn to be somewhat more than just an increase in track distance. The bank itself increases the induced drag (especially at greater bank angles) and therefore also increases the rate of descent - steepens the glidepath.
It seems to be forgotten here that some aircrafts are not well suited for either of sideslip or S-turn. For example some modern aircraft with slim rounded composite fuselages do not increase its rate of descent as significantly as for example Piper Cubs or Decathlons in a sideslip. In many of those composite aircrafts it is much more efficient to use an S-turn. Similarly there are also some aircrafts that aer no good for S-turns depending on sluggish roll rate for example.
if I was flying a normal approach and finding I needed an S turn, I might just be asking myself 'why?' and consider going around and flying a better approach
I think you missed the point in doing sideslips/S-turns. We practice this for being able to land following an enginge failure when a go-around obviously is not an option.
Full flap, just point the nose down. You lose height as fast as you like, and it doesn't speed up enough to bust the flap limiting speed. OK so you might end up a bit fast over the hedge, but it works if you've got 2km of tarmac runway.
The idea of making sideslips or S-turns is to be able to land even when you don't have that 2km tarmac, i.e to touch down at your aiming point rather than 500m after.