I would ask these people to try using their own names, John,
Marc, Mary, etc, and see if they can attain birth in the Pure Land through them.
Of course, they can’t and the reason why is that theirs are empty names without
any power.
As the Nembutsu is the saying of Amida’s Name it belongs to Amida and is infused with His infinite merits and Power. This is why it works in bringing us to the Pure Land at the end of our physical bodies. So, it is extremely important that our saying of the Name should be an expression of faith in Amida, and NOT in our capacities to say it often or seldom.
Each of us has his/her own personal relation with Amida Buddha who saves us one by one, having us always in front of His compassionate eyes. We do not need to be heroes, have the same visions or recitation capacities like Masters of the past, but simply say the Nembutsu according to our personal conditions while keeping in mind that Amida did NOT impose a fixed number of recitations in order to be born in His Pure Land: “say my Name perhaps even ten times”. This expression “perhaps even ten times” means ANY NUMBER from one to ten or to hundreds, thousands and as many as we can.