That's a brilliant anecdote, do you mind if I use it?
I understand what you're saying. There's a lot of truth to it and there's a fair number of people who feel the same way as you. I still feel we're better with more personalisation than less, but you are absolutely right that there's an uncanny valley as the computer starts to understand you.
A few years ago I worked for a very large loyalty program where I built customer personas. One of our participating companies was a clothing retailer. Big brand, nothing special. When profiling I naturally found some people spent more on clothing than others. For example, "people who x spend twice as much a year on clothing at ". The creatives used these profiles to create the ads and so naturally they included stylishly dressed individuals. The problem is that everyone spends money on clothing, it's just we happened to only have data from that one brand.