The best innovation often happens when working under constraints; often a drive for profit results in better service for everyone using the infrastructure. Of course this isn't the case 100% of the time, like your example of medicine, which is why I think that to get the best of both worlds you need a mix of government regulation with privatized capitalism. But I think it would be incorrect to dismiss the profit incentive entirely as being bad, and probably in the case of US infrastructure we would benefit from more privatization and not the other way around.
[1] http://money.cnn.com/2015/03/30/news/hong-kong-mtr-subway-pr... [2] http://www.newsweek.com/post-office-aint-broken-its-profit-s...