1.) well keeping that my daily job is very tight to information security i disagree here, sure all OS are hackeable but windows server 2003/2008r2 never took me more than 5m googling and 5 minutes hacking[Legally under contract] it to the bones[ppl get impressed when im in a rdp session making hell in servers and admins can't even see the processes running and their uber CA security/UAC/etc doing nothing except asking to open a word file LOL].
1a.) Mac OS X out of the box is lot harder to hack but still somehow easy[maybe 1h ] but at the end of the day Mac is BSD and when you harden the OS[you can google some guides] it become quite difficult to hack[Apple just make it insecure but the OS can be very sturdy but it affect the easy of use]
1b.) Linux/FreeBSD/etc are hellish to hack specially if you do things right, sometimes it took me weeks sometimes i give up but to hack linux you need to get extremely creative
1c.) OpenBSD true nightmare hellish level to hack, if i see an OpenBSD server and the root password is not "123456" i just label it as secure and save me a couple of months of pain[ofc can be hacked eventually im not saying is perfect but god damn is hard]
so concluding yes everything that has internet has a chance of getting hacked but there are vastly differences and is very short sight to assume all are equally insecure and when you work with security[the whole package not just the OS] you need to set levels cuz you have levels of hackers and level of interest for hackers, for example[this is from my own experience]:
level 1 - 3 Soho/small bussiness.) main OS windows SBS -- change to hack 9/10 -- hacker type 1-4[kiddos proving they are cool/ex-employees/spammers/etc] -- in this level you won't find a hacker able to break linux or OpenBSD
level 4 - 6 medium size bussiness.) main OS windows SBS -- change to hack 8/10 -- hacker type 1-7[kiddos proving they are cool/ex-employees/spammers/low profile industrial spionage] -- in this level is veru unlickely find a hacker able to break linux or OpenBSD
level 7-10 bank/gov/big corporation.) main OS Unixes/windows -- chance to hack 1/10 -- hacker type 7-10[higly skilled proffesional hacker/high profile industrial espionage] --in this level you will find hackers spending months/years try to hack their way regardless the OS cuz the reward is big enough for the effort in previous cases is very unlikely unless you piss off the guy and he make his life goal to screw yours[Gene simmons anyone??].
2.) ok sure but what are you using?? cuz like i said i never in ten years suffer from this at userspace level and i like i said using many different distros, so it call my curiosity what the F is causing that unless you have a propietary application compiled a decade ago to run on RHEL, in that case it could be but using FOSS software i can't believe it
There is no realy monetary gain in hacking linux, "outside of bank systems etc"and the only reason most avoid it, is becuase theres no particular version to hack. The diversity makes it secure, not the code itself. I'd lay odds that the linux OS ecosystem code base is a far clunkier mess of shit then most any closed source system.