This has always been true. However, the way that you should distinguish fact from opinion is analyzing the content. You should not rely on other people to explain to you which things are facts and which things are opinions.

In a world where people (in general) are capable of distinguishing fact from opinion (most of the time), you can omit the "I think", "I believe", "I feel" crap. In a world where people are bad at distinguishing fact from opinion, you can't rely on the "I think", "I believe", "I feel" crap because writers wouldn't be able to use them correctly.