Quite possibly. When asked about my build, I gave my most preferred choices. I stack as much Magic Resist, Armor, and HP as I feel I need. You won't always be the strongest thing on the field and your build will definitely have to deviate from its normal core.
You will need to learn to adapt and know when to build to survive and when to build to nuke. Diana definitely needs quite a bit of survivability or she is just going to drop dead. I don't place all of them on Diana at once, of course. I use my judgment to make a good call on what I need to do to win. If you're team is feeding hardcore, you're build definitely isn't going to stand up.
Sure, if you're miles ahead, any extreme nuke build will work with Diana, but that is always not the case. Learning to adapt is the way to come from 'certain' defeat. Building to survive is sometimes more important than building to kill. Also, I enjoy staying in the fight, not waiting outside spamming my Q waiting for someone to get low just to KS my teammates who have been doing most of the work. That's just being a ****. :/
Diana's ratios are remarkable, why waste them all building full nuke? You have plenty of high AP items with good survivability. You'll definitely make some people think twice about crossing you after they realize "She just came out of nowhere and destroyed me, even if I initiate on her first, she will still destroy me."
If I'm to get kills, I want to do the work and work with my team. I'm not going to be that guy spamming 1 skill every 2-3 seconds and then jump in just to nab a kill when my team has been working for a kill the entire time. One last note, Cho'Gath isn't a tank, if he's fed, he can just become tanky with stacks, so....3 shotting one isn't much of an accomplishment. I'm almost sure that my overall damage will be much higher than your build after a match too.