Tim Drake was probably the 3rd Robin I was exposed to. I knew Dick from the Teen Titans and Batman TAS cartoons and the first Robin I read in the comics was Damian. I didn't get to any Tim stories until a while later. He's my favorite Robin now, what does that tell you?
I'd been reading Barbara Gordon Batgirl for a while before I read anything featuring Steph or Cass. I don't like them the best because I read them first, they are genuinely better characters to me. Your point is moot, readers aren't going to fall in love with Duke just because they read him first. If they have sensibilities they'll probably find him boring.
And you don't like Duke either so stop trying so hard to defend him, stick up for characters who actually deserve it instead.