AFAIC a point to point line is the only way to go for interesting and realistic operation. On such a line, some spurs normally get served from one direction and some from the other. This generally saves the expense and trouble of having passing sidings everywhere, but there are circumstances where an industry must be served from the ‘wrong’ direction and so a passing siding is necessary.
My own pike consists of two main elements: a central roundy roundy - it was the first thing I built and it animates the garden and serves to entertain visitors - and a point to point main line which is the ‘real’ railroad.
But when I’m operating for real, the loop acts as a branch line while the main action occurs on the mainline which is just connected by a single track to this roundy roundy bit.
On a roundy-roundy type pike, I think we generally get into the habit of having a preferred direction of travel, which makes it difficult for us to imagine running in the other direction.
Sometimes this is because operation is just more reliable in that direction, or maybe because one direction seems esthetically more pleasing to us than the other.
This can make it difficult for us to imagine serving an industry on a roundy-roundy from a train running in the opposite direction. All the more reason to go point to point - that way you have no choice but to run trains in both directions!
