I think CalSurf has the right of it. Those roses aren't treated with care. I've been inside the (empty at the time) cold-storage room at the OLD Weeks facility.
Moreover, they all spend months sitting in cold-storage, until they're sold. And I suspect that folks in cold climates get plants held even longer.
I planted this rose in 1994, the year it was released. I"d been waiting for it, for a couple of years, as John Walden (late of J&P) had told me about it. HE said that the AARS trials, then, showed it doing exceptionally well everywhere it was trialed. He also said that, someone in that process had grown it as an immense free-standing shrub. That had to have been spectacular -- but OH! The THORNS!
We have it growing against a 12-ft.-high retaining wall. To its East is a massive "Secret Garden Musk Climber, and a gazebo. To its West is the gateway, which throws some shade. It does well there, and always has.
A few years back, some of its canes were very worn and gray. I removed them at pruning time and was rewarded with 3 new ones. The next year, I did the same. Not this year, but next year, I'll do the same, The plant looks great.
It reaches just above the wall ... say 12-ft., 4-5 inches. It spreads a bit fan-wise, but the canes are too rigid to arch, so it's easily contained. And we no longer tie it to the wall. It's self-supporting.