A beautiful day at Willard's Woods

Today was a nice, sunny, somewhat warm day (46 degrees!) so I took Spot and Shelby to Willard's Woods. It was a popular destination. We saw a bunch of dogs, mosts labs, which is kind of odd. When I go to WW, I'm still aware of Shelby because she's not totally trustworthy, so I bring cookies with me, if I remember. Whenever Shelby heels (on her own) I give her a cookie. If she's running around and I call her and she comes to me, she gets a cookie, plus a lot of praise. Occasionally, I just say good girl and release her. I'm trying to condition her that being next to me is a great place to decide to be, since that's where the cookies get delivered. It seems to be working. Well, this guy was walking his big lazy lab behind me and as he passed, he said, "oh, that's your secret. You give a cookie every ten steps." So I said, "well, I'm rewarding her for choosing to be with me, rather than running off." To which he replied, "Well, eventually you need to wean her off the treats." Really? I don't see why. What's wrong with rewarding your dog for doing something you like? True, eventually I hope it becomes second nature to Shelby to stay with me, but if I still need to give her cookies occassionally, that's fine with me.