لا صلاة كاملة إلا بفاتحة الكتاب
There is no complete prayer without al-Fātiḥah.
The quoted interpretation understands “no prayer” as negation of completeness, rather than an unconditional denial of the prayer’s existence. Thus in Hanafi terminology basic Qurʾānic recitation is treated as farḍ, while reciting al-Fātiḥah has the rank of wājib.
Omitting a wājib still has legal consequences; basic validity does not mean every required feature has been completed. Other schools, including the Shafiʿi school, treat al-Fātiḥah as integral to the prayer.