I assume that you're objecting to the use of the word "right" as opposed to, say, "privilege"?

The EU itself phrases freedom of movement as a "right"[0].

Arguably, every human should have the right to move to any country they want to, and in an ideal world every human would have that right.

That is obviously not the case now, but the rolling back of the partial progress that had been made, and the consequent creation of a boundary between the UK and the remainder of the EU that hadn't existed previously, is rightly condemned.

[0] https://ec.europa.eu/home-affairs/pages/glossary/right-free-...