Currently there are @ 3 locations to get genuine bios for the X series chips. Locking them down to accept only one kind of bios would be a futile thing to do the whole point of adding the thing is to open doors in the XBox not try and steer you through just one. Since most modders are adults (I say this refering to those of us over 18 years of age) we are all grown up enough to know that when you play you eventually have to pay and are more than willing to accept the consiquences.
In a nutshell, X3 has a backup bios on it in case you sneeze and hit the power while flashing so you can recover. Outside of the "biters" who like to play with things and unstabilize them.... you take the same chances with the chip that you take with your box when you try and put it in and screw it over. As adults we have to take it as its dealt so the extra "security measures" would be pointless if for no other reason than to say....
We are breaking security putting it in, what makes you think there isnt a group out there ready to defeat such a security feature if they are smart enough to screw over a bin file?