Yes, that is one of the goals of patents--to encourage innovation and risk-taking by giving the company that took the risk a commensurate reward by offering a limited term monopoly.
They get enough reward by being first to market if it sells. Everything else is just anti-competitive
And how is it so terribly detrimental to make other companies come up with their own original design ideas?
Flat, few to no buttons, clear screen, bezels, rectangular. That is the form factor that Tablets serve, and is what consumers want. So you have two choices, give consumers what they want or try something new that may or may not sell. Obviously the safer choice for a company is to pick one or two areas where you can distinguish yourself (color, size, aspect ratio) but keep the rest (flat, bezels, rectangular), thus detrimental not to follow what is currently selling, unless you get lucky.
Have you actually thought about this? Apple introduces a new iPhone and iPad every year. Do you think that next year's model will sell well if it doesn't appreciably improve on last year's one? What do you imagine would happen to Apple's profits and stock price if everybody decided to stick with last year's model?
Apple introduces a new iPhone and iPad every year because other companies are releasing other phones and tablets to compete with them. If there were no other competitors in the smartphone or tablet spaces, I can guarantee the actual improvement year to year for their devices would be substantially smaller. You have proved GP's point. Competition has given Apple pressure to improve.
Apple is not the only company with patents. So if the courts find that Apple has infringed an Android patent, Apple will have to pay a license fee, or trade some of its own patents to get access to that feature, or come up with its own features that are even better. How is that such a bad thing?
Notice how none of the Android makers are suing Apple without having been sued first. Why should you have to pay a license fee to say, "hey, people really like that feature! Let's figure out how we can do it too!" Or even worse, why should you be barred completely from doing it no matter what if they don't want to license the patent? In few cases does this result in "better" features. Better features tend to come around, not because of patents and having to work around them, but by a company saying "how can we improve upon what people currently like?". Generally patents just lead to inefficient designs used as a workaround. Notice I'm not saying that the benefits you tout never happen, just that they are rare enough that the benefit does not outweigh the cost to society.
Think of it this way, if everyone was allowed to just go "hey, people like that, we should figure out how to do it!" then everyone has to turn around and come up with something completely different and new to differentiate themselves. They will need to constantly improve and innovate to make their product better than their competition. Because they know if people like the thing they come up with they get the advantage of being first to market with a really good thing. Which gives them the ability to come up with more improvements before the competition. Patents just slow this entire process down.