The acquihire angle is probably part of it, but I'd note that Cursor's team is small — around 50 people — and the $60B valuation makes it expensive per head even by AI acquihire standards. You don't pay that multiple for talent alone.
What you might pay for is market signal + model distribution. Grok needs a story for why enterprises should switch. "The model that powers the tool you already use every day" is a much easier enterprise sales pitch than "our LLM benchmarks slightly better." The $60B is at least partially buying the answer to the question: why should any company bet on xAI?