In fairness, anyone can leave at any time. Your employer, regardless of size, has to be prepared for the possibilty that you'll quit for a better job, or for some other reason. It would be inadvisable to get emotionally attached to employees.
The reason you're less likely to get laid off at a small company is that small companies don't have the capital to hire indiscriminately, so they're less likely to have large inefficiencies. The number of employees is already as low as they can get away with, given their current revenue, so only a significant downturn in revenue would justify layoffs.
I disagree. There is a lot of variance in small companies. There is a lot of variance in large companies as well (the famous "it will really depend on which team you belong to").
I really think there is little correlation between company size and your experience at such company. The predictive variables (if they ever exist) are elsewhere.
If those people are assholes, the size of the company doesn't matter, your employment in that company will suck.
I stand by my original point: no obvious correlation between company size and quality of life inside it.
In my network we keep joining the same (relative small) companies because we roughly know the culture we can shape and create an environment
To everyone their poison so, I guess. I learned that I am a large company guy, by a nature and nurture. Other people I know are the complete oppossite. One thing I learned so, no employee ever is safe. Not even lifetime employed state / public servants.
I think the posters who remind people that the employer/employee relationship is a business one have it right. We as engineers should strive as best as possible what our specific value is to a company. We should not delude ourselves into thinking we are more to the company than that. When we cease to have that value, or they cease to desire going down that path, they might end the relationship.
I work at a company of roughly over 200 employees that is part of a much bigger org. Layoffs never happen where I am working. And one factor may be that HR has a different, in some cases personal relationship with their employees. That is certainly not the case in the parent org where large-scale layoffs happen every few years.
Edit: And I would not even attest that my company is one of those with a "heart", as you say.
There's a high chance you're just a "sweet summer child" who wasn't there the last time things were REALLY bad.
Might be survivorship bias though because the people that could have been laid off in the first few years cannot be there to tell the tale, of course.
While this is a respectable way to see employer / employee relationships, it does not apply to every company / employee out there.
In particular, I think this is very true for BigCo, where most people are seen as fungible cogs.
The smaller the company, the better.