Am I a terrible person because I don't want to talk to your child on the bus

Got on a bus leaving campus today. Went to sit at the back in my usual spot when I saw a kid sitting by himself. He seemed kinda young to be riding the bus alone (like 6 or 7 maybe), but there was no adult who was evidently attached to him.

A few people got on the bus at the same time as me and the child immediately went up to a couple of them and said "do you want to play with me?" After a couple of polite declines, the child proceeded to sit in about 3 different seats and swing around one of the handrails, with no intervention from the man I eventually discovered to be his father (via the repeated tossing back and forth of the child's backpack).

The child found a slightly more receptive audience when a group of girls got on a few stops later. They politely engaged in some conversation and what I think was an exchange of popcorn from the child. All the while I am staring at my phone, have my headphones in and am desperately trying not to make eye contact. I figured I was safe, until the gaggle of girls departed the bus. Then the child came and sat next to me.

Luckily he didn't try to talk to me. I mean, if I don't want to engage with adults in conversation on the bus, I certainly don't want to be trapped talking to a child for half an hour. I didn't even move my backpack off the seat next to me. Now maybe that makes me a bad person, but the bus was not that full. And also, go sit with your freaking dad!

Of course, being the ADD child he seemed to be, eventually he had to move from my seat as well. He went back to his first attempt, and chatted up the girl at the back of the bus. I had to laugh when she asked him if he was an only child; I couldn't decide what I thought the answer would be: yes, because he seems overly comfortable talking to adults, or no, or else he'd be able to entertain himself quietly on the bus.

At some point in the middle of this conversation, I was also offered popcorn, which I politely declined.

When his last captive conversationalist got off the bus, he degenerated into bursts of "who let the dogs out" and then asked a few more people (myself included) if they wanted to play with him and his dad.

I nicely said "no thank you", despite wanting to suggest a game called "shut up and sit down before I throw you off the freaking bus".

Seriously, there's a fine line between friendly and annoying. This kid couldn't even see that line anymore.