For me, I would count it. The way I look at visiting parks is that I went there and saw a game. For example, if I went to the All Star Game at a ballpark that I haven't been to, I would count it as visiting the stadium even if I didn't see the "home town" play...I still went to the park and watched baseball, at least that's how I see it. If I just visited the park and never went to a game, well I wouldn't count that...but you are right, it's all up to you and what you want to count. Chase on brother, chase on!
Like you said it's up to you. I think it does count, you are going there, and you are seeing baseball. It's not like you are going for a concert.
For me personally, it counts if I can put it in my "at the ballpark app." But really, it's up to you.