I'm trying to understand why every language has an infinite number of TMs that accept it
The correct version of the claim states that every computable language is accepted by infinitely many Turing machines.
Indeed, if $L$ is computable, then there is a Turing machine $T$ that accepts it. Let $T_n$ be $T$ together with $n$ unreachable states. Then $T_n$ also accepts $L$, and the machines $T_n$ are all different from one another.