I don't feel convinced by the argument. Maybe someone can help me understand better. - Virus infects human ACE2 suboptimally, therefore it's not lab grown. Why

I don't feel convinced by the argument. Maybe someone can help me understand better. - Virus infects human ACE2 suboptimally, therefore it's not lab grown. Why? Because a virus engineer is always going for maximizing spread rate? Seems plausible that less-than-ideal infection rates of humans could be a feature rather than a bug. - A polybasic clevage site was not seen in SARS-CoV... but it's function is not known. Okay? - The virus backbone was "0day" and not previously known to researchers. Seems like a feature that a covert bio warfare lab would desire. The rest of the speculation seems to ride on the assumption that the virus originated in China (despite evidence showing otherwise[1][2]), and their discovery seems biased toward any data to support that conclusion. 1. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1785/6012472 https://academic.oup.com/cid/advance-article/doi/10.1093/cid... 2. https://link.springer.com/article/10.1007/s10654-020-00716-2 https://link.springer.com/article/10.1007/s10654-020-00716-2