And possibly their unproven business model. Which can lead to managers making petty decisions about money and individual worth.
Since not every 10-person startup becomes the next Google. Instead, most of them becomes the next Froogle, that probably shouldn’t have existed to begin with.
In the past 3 years I haven't worked a full year due to the companies I worked for going out of business.
$MEGACORP isn't all bad. The pay is about the same, but I have much better benefits. For the first time in 5 years I have a 401K.
I've decided that I'm not going to work for another startup, unless I'm a founder. That way I have enough potential upside to make it worth the risk.
I work at a company this size. We've almost gone under quite a few times. We're still here. It's an interesting way to live. It's certainly not for everyone, but you get an enormous amount of influence and autonomy. The pay isn't "great", but I make enough that my wife can stay home with our three kids and the numbers in the bank account just keep going up.
Of course, a lot of that is lifestyle decisions, but working at a small company is a lifestyle decision as well.
Sure, startups aren't for everyone, just like big corporations aren't for everyone. For me, working for a /particular/ startup is unstable and risky, while working for startups generally has been extremely stable. Other people find them too risky, and that's fine.
Some people love the perceived stability of a large company. OTOH, big corps are known to do across the board RIFs, independent of how well a particular division is doing. Or killing off a whole department on what seems like a whim. YMMV.