The Rinnegan's visual insight is not on the byakugan or sharingan level.

[Megatolium]

Simple, Nagato WASNT looking at the rock, or it wasn't in his line of sight.

 

[God of TryHards]

The Byakugan couldn't tell the real one from a clone during the Naruto vs Neji fight. Naruto can make an exact replica of himself for starters. So even if he did realize there were rock clones around him, he still wouldn't be able to tell which could be the real one. Shows arnt meant to be dissected in real world logic. Of that happened, most if not all shows/movies would fail. Your rant is unneccesary.

 

[VongolaX]

Sad how people over-think it...

He was exhausted, simple.

When you are in the heat of the battle, it's hard to see chakra or sense it.

Nobody pointed out that he wasn't able to sene the clones presence either.

It's not plot or anything relatively-that for this matter.

 

[Xlad]

Since when Sharingan or Byakugan can see through transformations? Plus Nagato assumed that they were regular rocks.

 

[VongolaX]

Is that why Rinnengan can read the tablet better than Sharingan? Itachi couldn't see Kakashi underground in early part2. Sasuke failed to notice Jubito attacking Gamakichi/Naruto from underground. Kakashi failed to notice Black Zetsu under Obito and the list go on

Itachi did notice Kakashi underground, that's why he dodge his moves effortlessly and grabbed him to use genjustu.

Pein didn't notice Kakashi underground, and had to use shrine tensei, instead of dodging it.
(Wasn't fast enough either).