In the case of Wealthfront, it may be a cultural matter as their CEO specifically believes that negotiating your offer is a negative indicator: https://www.linkedin.com/pulse/20130708151000-56725-offer-co...
The only reason it is a bad sign is if they are paying more money simply to compensate for insane working hours or bad culture. That should be sniffable on glassdoor, or with a few well placed questions. Or look for the warning signs. E.g. "We have an onsite gym because we don't want people to leave the building all day".
First, even if you're dead set to work at company X, it's a good idea to get offers from companies Y and Z to help you negotiate. If X is primed for success, as the article recommends, then X should have no problem matching up because a good hire should bring in many times more revenue than what could be saved by pinching pennies on the offer. As a candidate, it's also great to be in a situation where you have multiple offers in the same range, because that allows you to take comp out of the equation and make your decision purely based on which company and role would be the best fit.
Second, it's OK if the first company you work at fails. Early in your career, learning as much as you can is more important than success or failure IMO, and failure can be a tremendous learning opportunity. The article recommends joining a company that's already almost certain to succeed; this means all the critical problems were solved before you joined, and all that's left is to execute. It's great to learn how to execute well, but it's also far from being the whole picture.