That and Britain is a bit busy elsewhere. Also not being able to handhold should make the (many) American problems, far more glaringly obvious and unlike OTL their isn't an Ally to take the blame. Should ensure a strong pressure to get things sorted out ASAP before any attack on Europe.Another point in favour of the US going into North Africa is that the British already soured their relationship with the French via the Mers El Kebir attack. I believe that still happened ITTL? It's a reasonable fear that another attack on nominally neutral Vichi territory, especially the most important one besides metropolitan France itself, could move Vichi france from Axis-subservient neutral to full on Axis power. If the Americans do it, since they still have a friendly relationship with the French that's less likely and, in the worst case scenario, the US cannot blame the UK for turning the French against them if the attack was carried out and botched by US forces.