Why do you care what data Amazon has about my living space? If you don't like it don't by a Roomba. Why do you always assume that people are rubes who are being duped by corporations, as opposed to people who are making a conscious tradeoff?
How many people have bought Roombas without knowing they would be sold to Amazon in the future? A quick search came up with 40 million units sold so far. Will Amazon offer a full refund to every person who doesn't want their data with Amazon? Or will they offer the option to completely stay off of Amazons systems, keeping the existing Roomba systems running?
If not, do you expect people to somehow accurately predict the future when making purchasing decisions?
Well of course, but the EU already has plenty of privacy laws to deal with that. That's no reason for the EU to object to this acquisition on those grounds.
It seems the primary issue here is that Amazon might be incentivized to disadvantage competing robo-vacuums on their marketplace. Which is not an unfair observation, but a bit strange given how many other Amazon-brand products it is already selling.