Thousands of links, including mentions in every major news publication. They aren't going to disappear or be retroactively rewritten.
Nor would the previous owner's past be reason for someone not to trust the current owner of the brand. You wouldn't stop trusting Bitstamp or BTC-e if they happened to buy the MtGox domain. Nor would someone reading an old NY Times article stop to research the past owner's history.
The grand vision of Coinbase isn't to capture as much of the Bitcoin speculation market as possible, it's to capture as much of the e-commerce payment market as possible by offering lower transaction fees and eliminating chargeback risk for merchants. If, for example, they took over the MtGox domain, and that helped stabilize Bitcoin and continue its push towards the mainstream, then "snitko's and 0.02% of our target market's image of us is tained by Gox's past" is probably a good tradeoff.