Why is the verb 'Ver' most often left out of these type of lists for forming the imperative of tú for irregular verbs?

Hola Michael

Ver is not an irregular verb in the imperative for tú. The verbs you see inside that lesson are the irregular ones. 

We say that a verb is regular in the imperative form for tú when it coincides with the conjugation of the 3rd person singular (he/she) in the present.

Ella ve el desorden = She sees the mess (present)

¡Ve el desorden! = See the mess! (imperative for tú)

The two forms coincide, so it is regular.

I hope this helped.

Have a look at this other lesson for more clarification.

Forming the imperative of tú for most verbs (affirmative commands)

Saludos

Inma