the word you are looking for here is 'yet'
"No one makes you take up a .xxx domain for your business."
Yet. in the Greater Sphere Of Things™ net neutrality is taking a fucking beating. content-ISPs in the Us and across Europe want to charge more for certain content. they lobby their governments and their governments lobby ICANN..e.g;
"we refuse to invest in the infrastructure necessary to roll out 8mps/max lines to every home in the UK unless you give us a reacharound with allowing us to charge for access to the BBCs' iPlayer tech, and youtube, and let us nerf torrent traffic."
The government doesnt want to pay for infrastructure, so its going to do its best to deal. non-internet-liberal governments (turkey, china, the islamic bloc) would love porn to be migrated to its own little ghetto online, so they can demand that their ISPs refuse to handle connections to that portion of the internet.
its much, much easier to blacklist *.xxx than "everything with fleshtones".
Your other, ZOMG .xxx will result in an explosion of porn are just behind the times in thinking that .xxx legitimises pornography online. I dont know what to say to these people; The internet is for porn, dude. perhaps some of their outrage is secretly borne of them living in a place where they might find their personal access to porn shuttered, so its less "there'll be an explosion of porn" and more "I'll have to justify why I should have access to a restricted service!!"
Bottom line: .xxx shouldn't be introduced. its a cute idea. it would have been cuter to have it with the original TLD stack and have those stacks enforced; .orgs for organisations .net for network providers, .com for commerce, .gov.AA for government/country websites, and so on and so on and so on... but if ICANN isn't going to regulate the 'proper usage' of TLDs, (something which is now an effectively impossible task) ICANN should NOT introduce one solely for pornography as all they would be doing is handing individual governments and ISPs a method for blacklisting and charging for extra content, as well as creating a problem in the future when governments start to lobby for "this porn problem to go away" - squeaky wheel gets the grease, and all that.
seriously ; you're creating a ghetto online for porn; for what purpose? where is the need? a sector of the marketplace and the people who lobby you find it objectionable? whats next, china wants a .dem TLD for pro-democracy websites? well, they have what, 2 billion people, you should totally treat that request seriously, right?