And my answer to this is "yes, absolutely!"
We all know there are people who subscribe to HBO JUST for Game of Thrones. Personally I subscribed to Showtime JUST for the Twin Peaks revival. And I'll cancel as soon as I watch the last couple episodes.
$10 per month is a couple trips to Starbucks. It's one cocktail at the bar. It's probably less than a large soda & popcorn at the movie theater. It's a Turkey Leg at WDW. Some of the more frugal customers will resist the urge to fork out for a half-dozen streaming services, but many others will not.
As for the volume of original content, it's not going to be anything close to another network. I cited 4 examples in my last post, and those could be spread out over the 4 quarters of the year. If Disney uses a weekly broadcast model for releasing content, I would envision them airing new episodes of maybe 2-3 shows at a time, spread over different genres and different age groups. If they release the series in bulk Netflix style, it's a new series maybe every 4-6 weeks.
Ultimately the audience will come from many different age groups and interest levels. Some will come for library content; different people looking for toddler programming, animated theatrical classics, 80s Saturday morning cartoons, '00s Disney Channel reruns, Marvel films and cartoons, etc.
Others will come for entirely original content from Disney, Pixar, Marvel, Lucas, etc.
Regardless of one's primary interest, the other stuff is just icing on the cake. Consider subscribing for the new, exclusive Star Wars cartoon and realize that the service also offers every episode of Clone Wars, every episode of Rebels and a bunch of other stuff you've never seen. Suddenly it doesn't seem like such a bad deal to subscribe for 3-4 months to catch the new stuff AND binge on the old. (And if people are enjoying it or forget to cancel, suddenly 3-4 months becomes 10-12 months.)