It hasn't been every company for me, but I've been through that a few times now... and I think it fits every BIG company I've worked for, and it happens a lot l

It hasn't been every company for me, but I've been through that a few times now... and I think it fits every BIG company I've worked for, and it happens a lot less at the smaller ones. Part, probably most, of the cause for me has been that the bigger companies have invariably had a much higher requirement for maintenance work than the smaller ones. At the big companies, I find that the senior and newbie developers are sharing the same tasking, so the newbies (and the less capable seniors) are generally satisfied, and the talented folks are underutilized and bored, and end up leaving. That also means that the higher the bar for hiring at the larger companies, the higher the percentage of dissatisfied developers.