I'm a bit conflicted on the whole thing.
Wolf whistling or otherwise calling out to women is not something I'd do, and I've always thought it to be pretty unpleasant.
My view was somewhat challenged after I listened to an interesting podcast episode (Love + Radio - An Old Lion, or a Lover's Lute), where a woman started talking to a guy who had called her out in the street. He was in his '50s, and she later sat down for an interview with him. Was an interesting and quite charismatic guy, and he reckoned that of every 10 women he called out to, he would get talking to half, and would get the number of one or two of those. And he would smash it in 9 out of 10 cases once he got the number. I don't tend to think he was exaggerating by all that much.
The interviewer was trying to point out that his cat calling was bad - but how on earth can you really say it is when he had such a strike rate, both in striking up conversation and, sometimes, progressing to sex?
I suppose there's a difference, though, in that much of the cat calling I've seen here in the UK (the podcast was USA) is not really used as a conversation starter, and is more of a show of force - showing off to mates, or otherwise proving masculinity by some overt 'alpha' display.