I don't think that's how the people at Valve think. These people usually have lifetime dreams to work at Valve well before they do because they admired those early games so much, which if you know the story were held up to very high standards internally and repeatedly. They spent their lives being hyper critical of their own craft and admire Valve because they don't a release subpar product as a rule. So collectively they'll have a LOT of collective ego tied up in whatever that product is, but it's not like "I own this", that would be highly anathema.