The big question is who replaces him at that stage?
It wouldn't surprise me if the hierarchy is waiting patiently to see if Vieira can hack it as a PL manager, then will go for him next summer. It's a decision that will unite the fans and with the greatest respect you aren't going to do much better than someone of his level.
Although I can get along with most of what you're saying, this is where I totally disagree.
I don't think an elite manager would come to us; if we wanted a manager like Conte, I think that ship has sailed. And even someone the bracket below that i.e. Rodgers would most likely be out of reach. However, the idea that our only other option after Arteta would be a fairly unproven Patrick Vieira isn't something I cannot see eye to eye with you on.
I think if we tried to get someone like Graham Potter, who has done a very good job at Brighton, I think he'd jump ship without question. I think Kovac has done a good job at Monaco, despite a tough patch he's gone through recently. He's within the realms of possibility.
If we tried for Hassenhuttl at Southampton, who also has done a great job under very testing circumstances at Southampton, he would enjoy the opportunity to come to us. I also think we could take Christophe Galtier from Nice, if we tried.
The point I'm making is there are absolutely better options than Vieira out there who are still within our grasp, even if they're not in the upper echelons of managers.
The other thing to note is that a lot of the players we've bought are very young so there is still a higher ceiling for them to improve and show what they're capable of. We're still lacking in some areas (RB, CB, CM), but a new manager would look to develop them to a significantly higher level than we're seeing now.
Make no mistake. Things are very, very bad right now. The worst I've ever seen an Arsenal side in my life. However, I don't think prospective managers or players view things as cynically as fans do. Whether that's right or not is immaterial.