You are correct, the issues raised in Biblical Errancy represent a challenge to Bible inerrantists, and religion in general.
You are incorrect in stating he "single-handedly disproves Biblical inerrancy."
He is entirely refuted here.
What we hope to accomplish within this site is to demonstrate that 'making claims' is easy – yet 'refuting unsubstantiated claims' is also easy. The rubber meets the road, however, when the claim-maker has to 'refute the refutations', which is the hard part. In the case of Dennis McKinsey, he fails entirely doing the latter.