Dude, what is your issue … Nethesis is a team of developers creating NethServer’s core, and selling it as appliances under the name Nethesis. You get fully working maintenance free appliances.
If you want to build them yourself, grab NethServer, and save a few bucks on the sale, but need to invest that as time to get things running smoothly.
It is a trade off, and a very honest one at that. You do not need Nethesis, but for those who can not spare a sysadmin tot be dedicated server admin, this is brilliant.
I am not sure why you see a problem with this.