The sex act is naturally ordered to procreation.  That isn't an opinion, it's a fact.  The only people realizing that homosexual acts aren't disordered are those who deny nature.

Funny that you quote Aquinas.  He clearly states in the Summa:
"I answer that, As stated above (A6,9) wherever there occurs a special kind of deformity whereby the venereal act is rendered unbecoming, there is a determinate species of lust. This may occur in two ways: First, through being contrary to right reason, and this is common to all lustful vices; secondly, because, in addition, it is contrary to the natural order of the venereal act as becoming to the human race: and this is called 'the unnatural vice.'"