Creeps and stalkers will often try to get a woman's contact info (email, phone, GPS) so that they can continue pursuit and evade scrutiny by the dating app's monitors, who are often very good at identifying and banning unscrupulous people who are not in it to win it, so to speak.
Of course, yes, a dating app's ultimate goal is meeting in person and striking up a real relationship. But anyone crossing that boundary had better be very sure that they've gotten to know the person and they really can trust that an encounter won't turn into a craigslist murder.
Interesting case in point. My erstwhile fiancee and I met on a MMORPG in 2008. She lived in Europe and I live in these United States. She inquired politely of our mutual friends and acquaintances and then promptly booked a flight to visit me. Then she applied firm feminine pressure and caused me to fly to Europe and visit her for a month. As it turns out, I was not ready for the kind of relationship she sought and we flamed out spectacularly. She could not have expected this after how it went on that MMORPG and based on the reputation I had there among the other gamers. But if she'd asked real-world friends... it might've been a different story.