Well yes, there are always shades of grey. It's not excusing anything, it's just analysing things critically rather than taking a simple-minded black and white view of everything.
Literally no-one posts on here as if Wenger can do no wrong.
Some people do post as if everything he does is wrong.
We haven't won anything for 9 years, that doesn't mean the whole 9 years have been an abject failure.
Wenger clearly has some failings, that doesn't mean he's a complete incompetent who can't do anything right.