Agreed that this is why Yahoo is pricing it this way -- but I imagine it won't stop the pricing feeling "wrong" to many people. "Why should I pay $500 a year for just a little bit more than I what I was getting for free?"
I would imagine, at that price point, it would drive people to use multiple accounts despite the irritation -- and that ultimately, because of that irritation, they might leave the service. Not a good situation for anyone.
I would imagine the people that need more than 1TB would be professional photographers who use flickr as a portfolio / advertising.
If you are such a heaver user that you need more than 1TB of space, you are unlikely to want to split your account into two and your would probably be unlikely to balk at spending $500 per year on what would be for you a business service.
A while back I was getting nervous about what Yahoo was going to do with Flickr, so I signed up for a $60/ year SmugMug account.
On the technical side of things, transferring the data out of Flickr wasn't a problem at all. If I remember correctly, importing ~9000 (~42 Gb) of photos from Flickr took less than an hour, and preserved almost all of the meta-data I had in Flickr (sets, collections, tags, etc.). It was so fast I almost didn't believe it. Of course 1 Tb would take a while even at that speed.
The bigger problem is getting people to use the new site. My Mom, for example, still goes to my Flickr page.
$50/year is for the ad-free. They are talking about the two terabyte plan. The (understandable from the perspective of the consumer) cognitive dissonance is, 999 Megabytes is free, but 1001 Megabytes is $500/year. How can two things, so close to each other, be priced so differently?
It's a very, very small number of people (though they certainly exist) that have photo libraries of > 1 Terabyte. And, and an almost insignificant number of people who have 1 Terabyte of curated pictures. (I.E. Eliminating Dupes, Poor Composition, Focus/exposure issues, etc...)
Flickr as backup doesn't make sense - backblaze, at $50/year, makes a lot more sense. Perhaps this is Flickr's way of encouraging people to start using them as a curated upload site, and not as a backup of their entire photo library.
I would imagine, at that price point, it would drive people to use multiple accounts despite the irritation -- and that ultimately, because of that irritation, they might leave the service. Not a good situation for anyone.