The sad reality is that a modern app like Chrome does look a lot like malware. It does a bunch of crazy things you might not expect a regular piece of software to do - manipulating file permissions and spawning large groups of processes, installing into a rather obscure part of the user's appdata folder instead of into program files, downloading arbitrary payloads from the internet and then using those payloads to modify executables on the user's machine...
It's always unpleasant when you get flagged by a virus scanner. Antivirus vendors basically ignore you unless enough of your customers complain to get their signature database updated. Hopefully in this case, since it's a high-profile application (Chrome), Microsoft will address the problem quickly.