I dont think anyone is not giving him a chance
what gets said on here (or in the pub) has no relevance on 'giving him a chance' on matchdays (when it actually matters)
right now, our only fit, senior striker has been pretty average in pre season. of course people are going to be worried.
hopefully, he will turn it on when it matters and not become another altidore type of donkey. but fans have every right to express their concern on here or in the pub
just as people will be too quickly (as you say) to write him off. other (and they have) will very quick to say he is better than lambert or tadic is better than lallana etc