well there's a saying that when the Velvet Underground was around only a thousand people ever saw them (maybe it was a hundred, don't remember very well) but every one of those people went out to start a band.

So is Poe influential in the way of VU or influential in the way of Bob Dylan.

The article doesn't actually say, and doesn't make much of an argument for him being the most influential (what argument there is, is more hinted at then effectively made) but given the many things he did I suppose the influence is widespread like Dylan and not direct like VU. If so - I believe widespread influence generally requires quality as well - and the article won't argue that as to him being the greatest.