On the contrary, my Apple computers have lasted longer and have been more reliable than any other computers I've ever used.
While my dad gets a new PC laptop seemingly every 2 years, my Macbooks last 4-5 years easily while taking a whole lot of abuse.
And since Apple products tend to hold their value really well, there's a thriving second-hand economy for these products that doesn't really exist for other manufactures. So older products get re-used by people looking for cheaper Macs or iPhones or whatever.
One last point: no one really upgrades computers anymore, especially not laptops. Desktop computers are rare in the home now, and the people who are really spending a lot of effort into maintaining their desktop rigs are gamers and video professionals. Upgrading becomes a moot point when a system lasts as long as 5 years. By that time, there is far newer technology and upgrading is no longer worth it or feasible (newer motherboard types, incompatible RAM pins, etc).
The best way to do good for the environment is to create a reliable product with sustainable materials that serves it's purpose for as long as possible and then continues to deliver value through re-use. That's exactly what they're doing and it's the smart way to do it - it becomes a natural part of the product lifecycle with no additional effort required from the customer.
Yes Apple do highlight how "green" they are, and you can read their annual reports and decide for yourself if it's a deserved point of pride or not for them: https://www.apple.com/environment/
I will say they are probably one of the more transparent manufacturers in the industry, with initiatives ranging from carbon neutral office buildings down to the material sciences level in their products.