* The maximum amount you can pay in a certain route is determined by the guy with the LEAST amount of money in his channel
So you'll end up taking a different route, most likely without you even noticing. You aren't forced to route through people with insufficient funds.
* Users can defraud each other in a channel, so they have to continually check if somebody is defrauding them.
But if someone does attempt to defraud you and you catch them, you can take their funds. That's a rather strong disincentive to try ripping people off.
* Unless you have a direct channel to your target, there is NO guarantee AT ALL that you can pay the person you want to pay.
Which is why Lightning is completely optional and you can still send regular payments to be confirmed directly on the blockchain, just like you always have done.
I don't see how any of these will result in LN "failing". The more accurate thread title would have been "There are occasions when LN transactions will be less viable than normal transactions", but I guess that doesn't have the same kind of alarmist fearmongering tone you felt the desire to convey.