It's not so much experience you need... although, that is helpful. But a steady head and a lot of nerve will get you far too. It's hard to tell always, who's going to make it or not, who's got what it takes.
While a world of difference, I started by AT thru with only 3 weekend overnights under my belt. 2,500 miles later I started another thru, and partly due to the expectations I now had, it was unbelievably harder..... I've seen people with far less experience than I do just fine, whereas at times my own fear gets the best of me. Some of the worst weather I've been out in, I've bailed off the trail, only to realize that really, at no point had I actually been 'in danger' or cold.... I was just afraid I would be. Reading 'Southbound' by the Barefoot Sisters, with no more experience than I, they battled a cold winter, storms and conditions that would have pushed me off the trail easily.... perhaps. But they had guts, and common sense, and each other.
Safety in numbers.
I know it's unlikely you'll find someone ready to go hike with you, but starting with someone you 'meet' here, on the trail, or on the fb PCT SOBO 2016 page, can make a difference. It doesn't sound like you'd be dumb and put them in danger; err on the side of caution, listen to experience of others, be as prepared as you can be. But having someone nearby can help, in the beginning as you get your trail legs. I know of many others who are looking to see when other people are starting, for this same exact reason, to gain some of that safety in numbers. That doesn't mean they save you or you're counting on them, but having people around can help. I know I'd like to start near others, since I don't know the west coast well, and I'm talking to everyone I can about weather conditions!
So short story long, no, it's not entirely irresponsible for you to attempt a SOBO thru. What it takes is guts, common sense, and the best preparation you can do. Nature is wild and dangerous even for the most experienced hiker, so listen to your own limits. It's ok to bail, but know that you might not be able to for a couple days, and don't expect emergency rescue....
And best of luck!!
Follow your dreams, believe in your Self and your Intuition, and if your intuition says this is a bit much, a flip flop or leap frog or any other kind of hike might be what fits your enjoyment and safety best. It's wild out there, but there's also a wealth of knowledge available nowadays, which I know is helping me a ton!
Hope to see you out there! I'm 'Nuthatch'