Re: Stupid, really.
Like all things, the thing that matters is the weakest link in the chain.
Assume the glass *is* bomb-proof and ram-raid-proof. All that means is that it won't break if you try. But the frame WILL give away. Hell, you could unscrew the damn thing if it came to it. Or just push it through. The glass might be "ram-raid proof", but the brickwork holding it in? Unlikely to be. Hell, you can kick bricks out of a wall if you had enough time, let alone what you can achieve in seconds with a sledgehammer.
It's a comfort to know something is "ram-raid proof" when it's lying, intact, on top of your stock in front of an empty window frame, I'm sure.
You don't need to invite trouble, and if you do then you're an idiot, but trouble will find you if you're not careful. In an ideal world, you can walk down the street telling everyone how expensive your new phone is and it not matter. But in the real world, being "ram-raid proof" just makes me think "What have they got inside that needs protection from ram-raiding?" and "what other way would someone get in if they wanted to?".
Like all things, simple systems make it much easier. DO NOT put stock on display, even behind ram-raid proof glass. Keep it out of sight, lock it away, and don't give customers free reign on it (I would predict you lose more from in-store theft than you do ram-raids, even in the worst part of town). You can't make things impossible to get at but hopefully you can make it slow them down enough for police / yourself to arrive, or have a quick-response security company turn up. Keep cash out of the till and in a safe as much as possible.
Don't pretend you can stop a crime happening to you. Take appropriate action that, when it does happen, your losses are minimised. God knows what it costs to replace ram-raid proof glass and/or the surrounding brickwork but I imagine it isn't any cheaper than just using normal glass and locking stuff away.
You can't stop someone breaking into a car, or mugging you. You can't. It's impossible. Cars are tested for a "3-minute" or whatever test, that they can resist someone unfamiliar with the car for that amount of time when it's first sold. Within months, most cars are compromisable within seconds if someone was really interested in doing so. If you are mugged you can't STOP someone taking your things, all your things, no matter how big and strong and skilled you think you are. At worst, they just kill you and walk off with your gear.
But you can make sure that the car alarm goes off, that they need to break the steering lock, remove the locking device on the gearstick, defeat the immobiliser, or whatever to drive it away and that - in the end - there's nothing of value that they can easily remove before they attract sufficient attention for them to give in. You can make sure that what's in your wallet can be cancelled in a trice (or tracked), that your phone is useless without your PIN code, that your bank cards don't have their PIN's stuck to them, that you aren't carrying a fortune in cash for no reason, that your house keys aren't marked with your address, etc.
Then, it doesn't matter what happens. In fact, every time someone then breaks into a car or mugs someone and comes away with nothing, they are slightly less likely to have a successful outcome which encourages them to try again (given the risks involved). But you can't STOP it happening.