It'd be impossible for Google Analytics to not collect data from a incognito tab without it knowing that it is incognito somehow (like if Chrome attached a header to all outgoing requests that said incognito=1 or something). But then websites would know you are in incognito, and find some other way to track you without leaving cookies on your box (like logging the IP address for the request and merging all incognito requests into one profile, which would be accurate enough).
What do they want Google to do? They warn you specifically of this anyway when you open an incognito tab:
"
You've gone incognito
Now you can browse privately, and other people who use this device won't see your activity. However, downloads and bookmarks will be saved. Learn more...
What do they want Google to do? They warn you specifically of this anyway when you open an incognito tab:
"
You've gone incognito
Now you can browse privately, and other people who use this device won't see your activity. However, downloads and bookmarks will be saved. Learn more...
Chrome won't save the following information:
Your browsing history
Cookies and site data
Information entered in forms
Your activity might still be visible to:
Websites you visit
Your employer or school
Your internet service provider
"