Rationale for following the predominant madhhab of one's locality

Answer

One follows a single madhhab not out of belief in its superiority but to maintain methodological consistency across fiqh issues -- mixing madhhabs creates inconsistency in practice, similar to a judicial system needing consistent rulings. Following the locality's madhhab is a matter of practicality (access to teachers, shared contract terms); choosing a different madhhab is not wrong. At the grassroots level, a layman with no formal learning who simply follows whichever mufti he consults is not burdened with any particular madhhab.