The article is talking about a fee for a particular activity, not "to hike" as a general thing. There are already other fee activities (and regulation of traffic) in that park, in other national parks, and there have been for many years. a fee helps in the regulation of activities that need to be regulated to manage the number of people doing it at one time, and cover costs produced.
I've been paying fees to camp for at least 50 years, and don't view that as some sinister expansion of government control or loss of a fundamental human freedom, that I couldn't camp for free like people did when there were only a few thousand visitors a year more than a century ago.
I think you will find even more regulation in the most crowded national parks, e.g. control of traffic in the busiest Yosemite trail areas.