Because in Europe LMS is not made for sport, its made for advertistment.
For example if Audi wins 24h LM then you got a milion tv advertistments about that how good Audi is and you must buy one...
And thats why we have that much cars (Peugeot, Audi, Pescarolo, Lola, ...) because everyone want to made all car with chassis and engine on their own, is a big advertistment.
But little manufacturers like Pescarolo and LOLA is trying to make it for sport but they dont have that much money like Audi...