Because that's one of the reasons they're kicking tires about a new stadium...lol.
As per Bo's comment, of course he didn't have to say anything, but he's trying to be the all good guy and promote his brand.
The reality is, most players hate the Skydome, so it's always questionable when a home player says "Yeah, it's a great place to play".
Anyway, I'm not going to keep going back and forth. For whatever reason, you seem to be of the minority of people that thinks it's fine, and there is a market that do think that way. Look at this thread alone, and the amount of people that are agreeing with and disagreeing with you. That right there should tell you why a new stadium has to be done.
Most of us want a ballpark where people from other cities get jealous of, and players want to play in. A ballpark that's not rated as one of the worst in baseball.
There's a reason this discussion is going on, and it's not because most people like the stadium that resembles and egg in the DT core is good enough, it's the opposite.