His point is certainly not wrong. Hypocrisy in the Church does mitigate the authenticity of the gospel. I'm simply not sure whether Wells' point is unique.
Perhaps the problem is less that postmodern culture uniquely demands authenticity and more that the postmodern Church fails to demonstrate it.
In any case John Bunyan's Pilgrim's Progress contains a striking paragraph that speaks to the same point Wells makes. Christian, speaking to Faithful about Faithful's harsh confrontation of the recently departed Talkative, says:
You did well to talk so plainly to him as you did; there is but little of this faithful dealing with men now a days, and that makes Religion so stink in the nostrils of many as it doth; for they are these talkative fools, whose Religion is only in word, and are debauched and vain in their conversation, that (being so much admitted into the fellowship of the godly) do puzzle the world, blemish Christianity, and grieve the sincere. I wish that all men would deal with such, as you have done; then should they either be made more conformable to Religion, or the company of Saints would be too hot for them.