I wouldn't for two reasons. Sega has the money to make SHENMUE. They just don't have the will. That's always ben the problem with SOJ management. A lack of leadership. I'm not putting ANY money towards a game that they should be doing themselves. What they are asking for is "hey guys.. were a company that makes billions of yen but don't want to spend the money. So can you not only fund the game so we can make it but also buy the game when its released. That way we will make money on a game we didn't have to put our own resources into it. Thanks."
And then think about the merchandise. Japanese games and merchandise are synominus nowadays. A crowd funded game which becomes a hit, will not only line up their pockets but any licensing and merchandise they make off of it. I've already invested my money into sega and they're going too much in a direction i didn't want them to go in which is why i took most of my own money out by selling those shares except the one i didn't own orginally. I'm not paying money on top of that for something they should do themselves.
Either way i'll still get paid whether they do it or not. And that's what you guys need to think about. Giving you're money to a billion dollar company to fund a game that could do well on the market and end up being a payday for the board and shareholders.
See that's why the rewards matter.
I've only ever funded one thing in this manner and that was Broken Age. I backed it for $100AUD I believe, which gets me a digital copy of the game, a limited boxed copy of the game and a T-shirt. That's basically a collector's edition for the price of a collector's edition in Australia (It also gives me a box set of the making of I believe, and a lot of non-tangible bonuses like access to betas and behind the scenes stuff as it comes available).
If Sega asked for funding, almost certainly any donation that comes close to the price of a game would mean that you get a copy of the game on release. In that way I see it as more of a 'pre-order' and you're putting your faith in the development team to make it good. I would only do that for select developers, but if it was Shenmue I would take the risk.
In that way I don't see it so much as a slight to fans, it's basically 'Hey, you said you would buy this game, here's your opportunity to do a very advanced pre-order to fund it, because it's the only way we'll take the risk'.
As for the possibility of making money elsewhere etc, people who back crowdfunded endeavours are not investors. They should not expect anything other than what they are promised as a reward. You put down $100 for a Copy of the game and a poster, that is all you are entitled to, and I don't know why anyone would be expecting more than that. If they don't deliver I believe you are legally enabled to demand your money back.
I can understand the principle of 'Sega has the money to do this themselves' but realistically, they never will. They wont do anything with the franchise, apart from sit on the IP rights and not let anyone else touch it. It's too big a risk and too big an investment. If the fans want it, they should be willing to buy a copy of the game via pre-order.
I guess in a way it's similar to Bayo 2. Sega could have funded that game, but they didn't. Instead of Nintendo stepping in to fund it, the fans could. Wouldn't you rather have a fan-funded game than none at all?