I'm in two minds
It's not good that it is difficult for anyone else to compete against Google, even if they are not actively doing anything evil - and Google has done nothing in this case, it's just that Streetmap wasn't as good.
But Google is a company just like any other, albeit a big one with lots of products and services, and can't be blamed for promoting their own products. To anyone who says "but that isn't fair" - if you go to the M&S website and search for a pair of trousers, would you expect them to also show search results from Burtons and Top Man in the interest of fairness? And give them equal weighting in the results? Thought not.