Why does apple not allow to install previos versions

long time ios user, getting mac osx side new job has 30 or mac osx users support . had question in head come while walking coffee.

why apple stop signing previous versions of ios not osx? can install snow leopard on new macbook pro if wanted to. can install 10.6 , not update 10.6.8 if didn’t want to. or if on lion if need reinstall can install 10.7, , not update 10.7.3. different ios devices apple forces install latest version, not mac osx

 

i'd know why too, sold old iphone 3g after upgrading ios 4, shocking! , kept calling seeing if downgrade, , no luck, don't understand why so.

 

Forums iPhone, iPad, and iPod Touch iPhone iPhone

• iPhone
• Mac OS & System Software
• iPad
• Apple Watch
• Notebooks
• iTunes
• Apple ID
• iCloud
• Desktop Computers
• Apple Music
• Professional Applications
• iPod
• iWork
• Apple TV
• iLife
• Wireless