It would be "very hard" for anything like the pro-democracy demonstrations at Beijing's Tiananmen Square in 1989 to happen again, a former diplomat to China said on the 30th anniversary of the event's final day.

On June 4 of that year, the Chinese military opened fire to end the student-led protests, killing a still-undetermined number of people and shocking the world with images of the crackdown — including that of the famous "tank man."

"Prior to June 4, 1989 and the whole spring of Tiananmen, you had a period of relative openness in China in which people were free to read, to discuss ideas, to interact with foreigners; it was a highly idealistic period as Chinese people got to know the rest of the world and recover from the Maoist period," said Robert Daly, a former U.S. diplomat to China.

Thirty years since the day of the bloody crackdown, China has grown steady into the world's second-largest economy, and its people have been accorded more freedom to travel and to choose their line of work. Still, that doesn't mean the spirit of 1989 is poised to again take hold.

"It's a consumerist society, so you don't have the same kind of idealism," said Daly, who is now the director of the Kissinger Institute on China and the United States at the Woodrow Wilson Center.

Other experts echoed the notion that China's economic gains have contributed to less interest in activism.

"Since '89, China has decided that politically they will clamp down on all dissent. They will concentrate all the resources on developing the economy, and they have done it exceptionally well," added Francis Lun, CEO at GEO Securities in Hong Kong.

"This has been the policy of Chinese government since '89: develop the economy, let people enjoy economic success so they will not ask for political reforms — and so far, they have succeeded," Lun told CNBC.