So

is popular with humans, but at least supperficially from my initial look it seems ELF thinks it should be less popular.
From a GoGoD search, it's the most popular pincer of the high approach and it's the second most popular move (behind the attach underneath.)
(the search was on a full 10x10 corner of the board, I've just cut the diagram down as the wider moves weren't so popular)
$$B a - 56%,b - 14%,c - 11%
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- Click Here To Show Diagram Code
[go]$$B a - 56%,b - 14%,c - 11%
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$$ ------------------[/go]
However - on looking at the games I found that I could understand (at least in a shallow 4k way) why the pincer was chosen, but ELF usually thinks it's still the wrong choice. On one occasion I found that ELF overlooked the pincer (presumably because it's so frequently a bad move) and when presented with the move it thought it was about 2.2% better than anything it was reading.
$$B 44th tengen - Hane Naoki v Goto Shungo. Moves 1 to 7
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- Click Here To Show Diagram Code
[go]$$B 44th tengen - Hane Naoki v Goto Shungo. Moves 1 to 7
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$$ ---------------------------------------[/go]
This seems to me to be a pretty tame use of the pincer for example. I've had this exact opening in a couple of my games recently while I've been investigating the pincer

, but in particular i found it in the 44th tengen - Hane Naoki v Goto Shungo. Black has a good reason to play 7 as a pincer as building infront of the shimari looks atractive (Choice of pincer is interesting to me though.)
ELF thinks this drops the black win % by about 2% though (not a truly game deciding swing.)
$$B O Cheong-a v Gao Xing
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- Click Here To Show Diagram Code
[go]$$B O Cheong-a v Gao Xing
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$$ ---------------------------------------[/go]
This looks like a reasonable time to play 2. White might naturally want to lend a little support towards the group in the lower left and/or build something on the left. A wider pincer in this case still seems to leave problems on the left side and since another move is needed, the tighter pincer makes some sense to me.
ELF thinks that before

this position is almost exactly even (white has slowly given away the slight initial advantage.)

Looses white 7.6% in this case so ELF seems to consider it a real mistake compared to attaching underneath.
Looking at around 12 further example positions from pro games, ELF mainly saw the 1 space low pincer as losing around 2-3%, with one occasion where it chose the pincer as it's move, one occasion where it didn't consider the pincer but thought it was 2.2% better than it's favourite move, and a few more occasions where it considered it a fairly serious mistake (around -7%.)