I don't think 2d rpgs > 3d rpgs. Also, Suikoden 2 is the only Suikoden that DOESN'T look low budget.
If they made Suikoden VI 2d, that would be distinguished mentally-challenged. That aren't going to do it. That would alienate newcomers because most of them are idiots and wouldn't be able to get into a 2d rpg. Suikoden needs newcomers to survive, and people who alienated the series with Suikoden IV.
Suikoden fans think about sales and how the series will survive. Making it 2d would just kill the series. If it's going to be 2d, it'll be 2.5d like Suikoden V.
I'd much rather they be given a reasonable budget and at the very least make it on par with Final Fantasy X.
How are you going to a market a 2d rpg for the Wii in 2008 for an already niche series, who's last game totaled around 300-350k worldwide?