I like the analogy from from Fr. B at Rationabile Obsequium
(If I might suggest an analogous argument - a promiscuous young man who makes a decision to be faithful to his steady girlfriend may be a first step towards a healthier and more moral sexuality. I think any sensible confessor or moral theologian would see that. HOWEVER, that doesn't mean that extra-marital sexual activity is something good or something to be approved of.)
Another sensible quote from Dr. Janet E. Smith, over at Catholic World Report.
Christ himself, of course, called for a turning away from sin. That is what the Holy Father is advocating here; not a turn towards condoms. Conversion, not condoms!