I think the real concern as someone noted is the 3 hour cutoff. Most games have 3 hour time slots for scheduling so when it goes over it cuts in to another show. That means networks have to schedule something relatively unimportant that can be easily pre-empted or bumped. That may be the real problem and not what fans think. Bottom line on the fans is there are more attending and watching than ever in history. So this is in many ways to me an engineered problem.
I looked at the article and one of the graphs compared game times beginning with 1915 which I think is not comparing apples to oranges. You cannot compare game times today where there has to be built in commercial time. And it is not just the time between innings. There is a commercial break between most pitching changes. I have heard talk about reducing the number of pitches a new reliever gets on the mound but that time is not only needed so the guy can throw 8 pitches off the mound it is needed to complete that commercial.
To be honest watching on TV game times are not that burdensome because I fast forward through the commercial breaks. I rip through that 3 hour game in about an hour and a half, assuming I have control of the remote.
Fortunately in my house I always do.