Word in the industry is that AWS is insanely profitable, so they've got not problem finding the money to hire the help.
My gripe with EBS is that hiccups in EBS cause my Linux instances to "lock up", consume 100% CPU and become unresponsive. AMZN is providing their own Linux distribution and drivers for the EBS devices so they can also attack this problem by patching the Linux kernel.
The hiring market is very competitive right now. It is hard for Amazon (or anyone) to hire good engineers. I think this is exacerbated by Amazon's lack of perks. My opinion is that if Amazon wants to hire the best of the best to work on AWS products they need to stop being so cheap ("frugal") and match the perks (and pay) other software companies offer.
My gripe with EBS is that hiccups in EBS cause my Linux instances to "lock up", consume 100% CPU and become unresponsive. AMZN is providing their own Linux distribution and drivers for the EBS devices so they can also attack this problem by patching the Linux kernel.