Re: Not really a big deal
Anti virus software scans software running against a blacklist of things that shouldn't be running.
You can configure OS's (even Windows, with only tools available out of the box) to run nothing but a whitelist of programs and filetypes that you specify is safe, essentially making the anti virus blacklist pointless.
One could argue quite convincingly that cloud managed anti virus is worse than the disease it's supposed to protect against, as it offers the ability from the command console website (or by extension from the vendor or anybody hacking the website or command channels) to tell the anti virus client to execute commands on the computer it's supposedly protecting, including downloading and installing things making the AV client a potential attack vector even if the network it is protecting is otherwise secure.