O uso de Since

Olá,
Sempre aprendi que não se pode usar "Since" no Presente perfeito,veja:

I study through the English Experts Sinca last year (Errado)
I have (Been studying) studied Through The English Experts Since last year (Correto)

Sendo assim,estaria correto dizer que neste trecho da música,eles erraram usando a frase "Since I dont Have you":

I don't have plans and schemes,
And I don't have hopes and dreams.
I, I, I don't have anything,
Since I don't have you

Me ajudem se possivel,Obrigado