You have 3-4 years socked away and you're wringing your hands over this decision? I think the answer is no, you shouldn't. That kind of runway should make the decision an absolute no-brainer if you really want to strike out on your own.
People with 6-figure salaries and 3-4 years runway tend to be calculated risk takers. They don't jump in unless it looks like there's a decent probably of success. That doesn't mean they won't take any risks, just that they want the odds to be in their favor.
All that said, I'd say go for it. You can always get another job, and 3-4 years means you won't be in dire financial straights when you're looking. Starting your own company often uncovers other opportunities that wouldn't otherwise be there if you just sat in a secure day job, too.
I'm not saying this to be mean (plenty of startups fail), but your startup did fail. Your experience isn't exactly a knockout blow to the argument that anyone hesitating to jump in even though they have 3-4 years of runway might be too risk-averse to be successful with their own company.
You seem quite willing to deem someone not ready or not in a position to give advice. Also, before you make a bold claim about someone's character it would be helpful if you read their previous comments.
Opinions were asked for, I gave mine, someone disagreed with me, and I disagreed with their reasoning. Nobody's feelings should be hurt, grow up.
I just thought it was kind of odd that you'd suggest someone might not have enough risk appetite for a startup, and then when someone else replies that most entrepreneurs take calculated risks, point out that they failed. Failure is a part of risk. All those folks who did take the risk of starting a startup...well, most of them failed. Does that make them unqualified to give startup advice? Kinda contradictory, given your original point.
Here's another bold opinion: if some jackass like me can persuade him not to do a startup by pointing out that startups aren't for the risk-averse, then he probably shouldn't be doing a startup.