This is a user-to-user forum. I don't work for Microsoft now, nor have I ever. The moderators here are volunteers and users just like you.
I completely understand your frustration. However, Microsoft employees are not likely to read your comments in this forum. If you want Microsoft to see your comment use the Smile button in Excel or add your comment to others at the UserVoice link I referred
you to earlier:
Enable pictures or photos to be inserted into the header of an excel sheet
If you scroll through the postings on UserVoice you will see a reply from Microsoft's Dan Battigan dated May 4, 2016. He's the person in charge of Excel for Mac. He said, "...we
see the input on this idea, and through other feedback channels. The best way to influence the timing is to continue to add votes, etc."
Feedback sent using either the Smile button in Excel or the Uservoice form IS read by Microsoft employees. Here, in the "community" forum, the audience is limited primarily to fellow users of Microsoft products.