If $L$ is an APX-hard language, doesn't the existence of a PTAS for $L$ trivially imply $\mathsf{P} = \mathsf{NP}$?
Since for example metric-TSP is in APX, but it is not approximable within 220/219 of OPT [1] unless $\mathsf{P} = \mathsf{NP}$. Thus if there was a PTAS for $L$ we could reduce metric-TSP using a PTAS reduction to $L$ and thus can approximate OPT within arbitrary precision.
Is my argument correct?
[1] Sanjeev Arora, Carsten Lund, Rajeev Motwani, Madhu Sudan, and Mario SzegedyChristos H. Proof verificationPapadimitriou and the hardness of approximation problemsSantosh Vempala. JOn the approximability Of the traveling salesman problem. ACM 45Combinatorica, 3 26(May 19981):101–120, 501-555Feb. 2006.