UKH

Quick plumbing question. 
All the toilets in my house have the water feed pipe coming up through the floor on the left, but the piping routes up and across, under the cistern, over the waste pipe and into the cistern on the top right. All the toilets also have holes for the water feed and pull handle on the left too (currently capped) and could be fitted the opposite way, so why waste the copper and feed into the other side of the toilet? 
I’m refitting the bathroom and thinking of switching it. Any reason why not? Am I missing some plumbing fundamental here?

thanks

Nope, no reason at all.

 I am not a plumber 

 You’re not missing a fundamental I speculate that the cold water feed is copper with no flexible connector  ?

 running the pipework as you describe allows a few millimetres of movement to do the final connection Before it is tightened i

All of the above now unnecessary flexible tap connector with an isolating valve  A tap connector is what makes the final connection although it is not a tap 

After years of having the flush on your right you will not easily adapt to it being on the left. First world problems, but it's like moving a light switch, you will still reach for where it used to be.

The original plumber was probably either too lazy or too stupid to rearrange the cistern internals.

If it's a very old installation (maybe more than one cistern ago), there may not have been a left-feed option when it was first plumbed in.

Fortunately we’ve just moved into the house, so shouldn’t be too much of an issue.