Well first, it's a little late to back Yooka Laylee regardless, so I don't see why anyone is being "scared off" because MN9 sucked. Second, YL and MN9 are two very, very different Kickstarter projects. I'll get to that later.
But to address the question, people don't seem to understand what Kickstarter is.
I've had to say this a lot here and on Reddit. Kick starter is NOT:
* A pre-order.
* An investment (you do not earn profit or get a cut from your donation).
* A purchase.
* A contract.
From their terms of service - "Kickstarter does not guarantee projects or investigate a creator's ability to complete their project. On Kickstarter, backers (you!) ultimately decide the validity and worthiness of a project by whether they decide to fund it."
* A donation to a company with a generally intended purpose.
Once you give them your money, for all intents and purposes it's gone. There's no guarantee of a finished product (I backed Unsung Story and got nothing at all). There's no guarantee that the end product will look ANYTHING like what you were told up front (MN9 says hi). The game could end up in development hell for eternity (Star Citizen, which I also backed).
Kickstarter has always been and will always be a calculated risk. If you think you can say goodbye to $X forever and hope for an outcome, then Kickstarter might be for you. I got burned on a few project and am now VERY selective in what projects I'll back. MN9 smelled fishy from the start, so I didn't back it. Sir, You Are Being Hunted looked fishy from the start, so I didn't back it.
I have had, and continue to have, absolutely zero doubts about the end-product that will be delivered by Playtonic. Playtonic is a tight-knit team of developers who know each other well, with a boatload of shared experience in the exact type of project they're making. MN9 was, what, one director from a couple of the Mega Man games on it? And that's it. The connection between MN9's development team and the original Mega Man team is barely 1 guy. Yooka-Laylee's team is a huge chunk of the original Banjo Kazooie team.
Backing Playtonic was a calculated risk that I know will pay me back in dividends. I have zero regrets and so far I would absolutely back them again if they announced another Kickstarter after Yooka Laylee came out. ... though I think they plan to go into hiding and use the proceeds from YL to do whatever they do next. More secretive, less answering to outside parties.
Make the forum great again.