[p_l]

It took extra long because for various reasons it was the officially blessed architecture (specifically, HP-UX on Itanium) for running Oracle databases, leading to HP suing Oracle when the latter bought Sun and essentially declared HP-UX is to soon be EOL'd

[dvaletin]

Okay, but we speak about Linux here!

[p_l]

Ah, somehow I figured out you were asking why IA-64 kept on for so long - as in the architecture in general - not just in Linux.