As a native Chinese mandarin speaker all of my other Chinese friends and family I spoke to were completely shocked at how well he spoke Chinese. Yes, his tones are off but the majority of non Chinese speakers tones (and sometimes my tones are off when I haven't spoken Chinese in a while) are usually off so when you take that into account, and how he said he wanted to learn Chinese because of his wife's grandma who only spoke Chinese, its very cool to see someone in his position (as a multibillionaire ceo) where Chinese has become a hobby and a passion.
Who cares? He gave something a go and gave it a shot.
I'm pretty sure his goal has nothing to do with speaking perfect mandarin.
If people are going to judge him and spend their days writing articles about judgement on him and giving something a go, it's a little sad in my eyes(not necessarily referring to the article itself as such and i've only scanned through it so perhaps i'm missing something).
I think this was an incredible move by zuckerberg and he should be applauded. I studied mandarin in grad school and then spent some time in China studying female chinese consumer behavior. Though my study participants were excited to practice their english with me, i was shy to practice my mandarin with them and I totally regret that as now my mandarin is almost gone. By truly taking steps to communicate with the very important Chinese market, Zuckerberg once again demonstrated his leadership skills by being brave as he made himself vulnerable to mistakes. I'm sure the many people in China who idolize him were also humbled to see him try something outside the comfort zone of a billionaire ceo.
I've only been studying Mandarin for a few months, so I can attest to the difficulty of understanding tone. Having learned a few languages over the years, including Spanish, Japanese, French, Italian, and Tagalog, I'd say that the hardest part of the learning process is getting the courage to speak to a native speaker without looking like an idiot. It's hard enough to order a meal in the language, but an on stage interview on camera is another level entirely. I applaud anyone brave enough to do that after just a few years of study.