Is there anything wrong with someone who performed tayammum and then prayed while wearing his shoes?

It is permissible to perform tayammum when water is unavailable or its use is difficult due to illness. Tayammum has no relation to the feet. It is permissible for someone who has performed tayammum to pray in their pure shoes; in fact, it is a good and legislated act to establish the Sunnah, as long as it does not lead to disturbance or harm.