Did I claim that we should? All I pointed out is that it is a mistake to state that Mary is dead, and that the traditional Christian understanding of the communion of the saints (which includes Mary) is founded on the priniciple that the members of the Church should pray for one another. Thus, traditional Christians - such as the members, like myself, of the Orthodox Church - believe that the living saints that have passed through death should pray for us, just like I should pray for my wife.
I will say that we should not worship any one but God alone. "Pray" is a much more nebulous word though. According to Merriam-Webster, it means both:
"to address God or a god with adoration, confession, supplication, or thanksgiving," AND...
"ENTREAT, IMPLORE -- often used as a function word in introducing a question, request, or plea "
Even in Scripture, it's used in it's more casual form:
Ac 8:34 - And the eunuch said to Philip, "About whom, pray, does the prophet say this, about himself or about some one else?"
Lu 14:18 - But they all alike began to make excuses. The first said to him, 'I have bought a field, and I must go out and see it; I pray you, have me excused.'
When a traditional Christians speak of praying to the saints, they mean praying in the more casual sense. Asking. Specifically, asking for them to pray for us.