What Is The Point of an OS Upgrade That Cripples Your Phone?

One of the figures that Apple is very keen on trotting out  whenever it gets the opportunity is the one that measures the number of phone users who have upgraded to the latest version of the OS. The pitch usually goes something like this: 99% of iPhones are running the latest version of iOS just seventeen minutes after it was released to the public, meanwhile the latest version of Android is only on three phones despite being available for three months. (I'm paraphrasing here)

However Harvard professor Sendhil Mullainathan has been doing some research using Google Trends that suggests that large numbers of users are immediately disenchanted with their iPhones post-upgrade. The search term 'iPhone slow' goes ballistic on Google immediately after the release of a new version of iOS. This NYTimes article has more details.

So the question is: does Apple deliberately sabotage performance of older devices in the way it codes its upgrades or is this just the result of trying to push older hardware to places it should never be taken?

Either way it doesn't look good for Apple. A failure to properly test upgrades on older devices or a deliberate sabotage that goes beyond built-in obsolescence.

A little bit of honesty wouldn't go amiss here. If an older iPhone isn't up to running your shiny new version of iOS then don't provide it. Sure those ridiculous keynote graphs won't look so good, but a company allegedly so customer focused as Apple shouldn't protecting the customer's investment count for something?

After all, when they find out they can't have the upgrade those users will probably choose to buy a new iPhone anyway, so why dupe them?