yes, but that is a very simple thing to do. your ISP have only a few gateways, youre connected to one of them at a given time, and all your packages requests are logged there. You simply do a db query on destination IP addresses for IP address assigned to you router, getting unique results, matching those results to any dns table, remove some standard calls like ms / apple update servers and similar stuff and you get a general history of your internet traffic.
And yes, of course, noone is going to do that for an average Smith.
I was only pointing out that your internet traffic is not as anonymous as some thinks, and your ISP have a lot information related directly to you and your browsing pattern no matter which dns are you using.