The problem with some Android manufacturers is that they have to make a version of Android for each particular model.
Some phones run one skin... some run another. That's why it takes months before an Android phone can be upgraded to the latest version.
But really.... they would rather not take the time to do that. They are busy pumping out new phones every month.
If you're a company with over a dozen models coming out every year... you focus on new sales... not supporting old models.
If I buy an Android phone tomorrow... what are the chances it will run Ice Cream Sandwich someday?
But it's also Google's fault. They come out with new upgrades several times a year. I know they call them updates, but they aren't. They're mini upgrades. apple issues updates. We get security improvements, bug fixes, and sometimes a minor feature. But Google delivers upgrade features. Sometimes they change the way software interacts with the OS, and even the hardware. There is no way that OEM's, working on several phone releases each year can keep up with that. So there is no sync between new phones and new upgrades. The more change a phone model has, the longer it takes to produce, so we see the strange fact of a new phone coming out with an OS version one or two versions behind. And often, they never get upgraded. Samsung, the most popular Android manufacturer is famous for that. But the others do it to.
The problem is that they don't know what Google is going to do with Android, so they can't anticipate it in their newest designs. I get a very strong feeling that Google doesn't know what they're going to do with their OS a year in advance. So much of it is posthaste in competition with what Apple does. A bit of a "let's do this before Apple does, quickly!" But it isn't well thought out, which is why most reviewers say that Android always seems unfinished, and crude.
So they do one better with notifications, but it's not nearly as much as they could have. Now, Apple does something that Android fans say is a copy, just because it comes down from the top of the screen, as though there is another way to do it. But Apple's is vastly more sophisticated. Likely, they've been working on it for years.