It's a serious art but only if you're willing to dedicate 10 years of your life to gaining proficiency, and then the next 20 years to master it.
Tai-Chi was one of, if not the most feared art in China in its time. It's masters were the most peace-loving of folk, but also the most deadly. It is considered the highest expression of the chinese internal arts, above Pa-kua and Xing-Yi, and was even more feared than Baji-Quan (known as the "bodyguards art".
Tai-Chi is only for the most dedicated of people, and that's why most people think its cack when theyve done it for 2 years and can't fight for **** at the end of it. Not to mention it's increasingly arre to find teachers that not only can fight well and train to fightm but actually teach it as afully-fledged martial rt.
You need to train Chen or Wu to be a good fighter imo, but that's just imo.
It's not a martial art for people looking to get harder quickly, it's a way of life. And it wasn't for me.