How many times have you heard someone say, "I don't have to worry about crime; I live in a gated community"? Yeah, the electronically-locked gate may stop criminals from driving in, but not from walking in!
That stylish gate is more of an ornament than a crime deterrent. It may very well be a lure to thieves, since it suggests that there's a lot of valuables in those houses. The gate may even suggest complacence with tougher security measures among the homeowners.
The big iron gate may even encourage residents to leave entries to their houses unlocked or windows to their child's first floor bedroom open overnight. Any reason a pedophile can't slip through the gate while it opens for a resident? And that assumes the perp isn't bright enough to just walk into the premises.
The giant gate may as well have a neon sign overhead that says, "Welcome! We Have Lots of Valuables in Our Homes!"
Might a burglar assume that every home has an alarm system? No. He'll avoid those that have signs of an alarm system, but he'll continue poking around till he finds evidence of an unlocked house. An alarm system is worthless if it's turned off and a door is unlocked. This risk-reward calculation is too juicy for a thief to pass up.
And here's another formula to consider:
Gated community = more money = more empty homes while residents are on yet another vacation.
Still think that gate protects your community? How often have you forgotten your code or the keypad malfunctioned, and you waited for the next resident to open the gates, and you slipped in right after them? How easy was that?
How often has the gate mechanically been broken and you zipped right on through? Even a gateman who buzzes people in may not be on the ball. And even if he is, you should assume that many service technicians are given entry codes. It's not an issue of how or if a thief can get in, but who.