I graduated in 2012 and my first job out of college was Google. So far I have put about 50k per year into savings over the past 6 years not counting my 401K. If when I am 35 there is significant risk of downsizing I would be fine with getting let go. If I did get fired at 35 I might just decide to retire at that age or start my own business for fun like Citizen Kane.
Some people here are blaming the short careers of engineers on their skills getting out of date with current technology, but then why wouldn't we just use our employers tuition reimbursement to learn some new tricks?
I think the real reason is that we are very well paid. Why fight so hard to keep your job once you have enough in the bank to live on for the rest of your life?