Pig-simple and robust.  Obviously aimed by simply man-handling the vehicle, and able to buzz instantly away from the tell-tale backblast whenever it was fired (a signal problem with recoilless rifles). 

 

Infantry never have enough high-caliber direct-fire support, and have plenty of incentive to improvise (as witness the fact that all the Cold War man-portable and vehicle-mounted antitank missiles have been used readily and without stint by the men on the ground for bunker-busting and house clearing in the Sandbox, expense and "unsuitability" be damned). 

 

The fact that the French fielded over 800 of these improvised SPG's implies that they had a worked-out doctrine for their use, and likely they'd still be employed unless the French found something equal or better to serve the same sort of function in their light "leg" and airborne battalions.  So what replaced these gun scooters? 

 

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