Its not so much $71 per person per day, but its a huge chunk of money to pay at one time.
As far as comparisons to sporting events or other entertainment venues: Yes, sporting events, concerts, Broadway shows are expensive and comparable to Disney. BUT, and this is a huge BUT, if I go to a concert, its a one time charge of say $80. If I take my family of four, for example, it may be a one time $300-ish charge. I may have to pay for parking, but it will only be once. I may not buy any food or sourvineers. I may also pay for one night at a hotel for $50-100 a night. But, that is it. Its a one-time event, with one time charges.
Going to Disney, most folks don't go for one day unless they are local. They go for multiple days, a week or longer, so that would be like taking a family of four to 5-6 concerts each week, or 5-6 sporting events each week. Most folks really don't do that, so its hard to make a direct comparison for shows, concerts, etc. to what you pay at Disney.
Disney is expensive. Not everyone has recovered from the recession (i'm still not where I was financially in 2008, for example) and costs keep going up. And, what you get for the costs is going down. To be honest, we're now priced out. Could we find a way? Probably. But our trip earlier this year in February was in crowded parks with long waits and grumpy CMs. And since then, prices for parking and other items have gone up. That really doesn't make me want to go back.