I posted this in another forum that you had asked this question as well. Just my 2 cents.

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Assuming the time frame of your scenario takes place after the Battle of the Pockets and the Points, several factors would have greatly worked against such a move: (using 20-20 hindsight myself)

- Assuming Japanese reinforcements couldn't be brought in fast enough, Japanese air support could. They could easily wreak havoc on a USAFFE counterattack. Only the central and lower half of Bataan had double canopy forests. The SPM's and tanks would have had to take the main roads. They'd be sitting ducks to Japanese air support

- USAFFE artillery could only reach so far. If a counterattack advanced north far enough, they'd have to be brought in closer to the action which would make them vulnerable to air attacks again. Also the I Corp lost most of its artillery when they retreated to the second line. They may not have enough to support a push on the west side.

- The Philippine Division which was the bulk of the troops that were trained enough to conduct coordinated offensive maneuvers already tried a counter-attack to restore the Abucay line, and they failed. The ample artillery support that was available were ineffective because of the terrain and lack of accurate maps and communications. They had counter-attacked at a time when they were still strong and had relatively few casualties and still failed. A counter-attack after the battle of the Pockets and Points wouldn't have been promising. They were already weakened and suffered heavy casualties from those battles.

Their situation simply stunk. Not a whole lot of options. They were stuck between a rock and a hard place.