The reason is that NIP-57 is badly designed, with no interoperability with existing LNURL or LN Addresses. In fact, you cannot support both zaps and normal LN Addresses or your profile.

Read the NIP.

People celebrate that it was merged as a sort of accomplishment.

No, it was merged because it turned out feedback was being ignored and multiple parallel implementations were being pushed, regardless of the issues raised or improvements suggested.