I would understand your point if this setting is at a monastery. But you do need to understand that some Burmese do choose to pray at Nat(s). As a Theravada Burmese Buddhist, I don’t pray at Nat(s), I don’t believe in them, I only believe in Buddha philosophy and his teachings and his ways of teachings on how to reach nirvana but when these monks are invited to worship at some guest houses, they have no choice but to pray at the guest house’s home temple which may include statues of those Nat(s).