They already are, as proven by the fact that despite all the failures of Windows and OS X on tablet computers, the iPad sold hugely straight out of the gate. All you have to do is see how Apple achieved 17% growth with all of its standard computers while Windows literally saw negative growth from all vendors except Toshiba to realize Apple's lock-in appears to be a good thing to them.
The only people who seem to agree with you are the ones whose lives or hobbies depend on that 'openness' that is so loudly touted on these boards. Simply put, Apple's sales are increasing while everybody else's but one have stagnated.
This is one place where I will partially agree with you, but considering the successes of the iPhone, I highly doubt Apple will cut its prices on the newest models, though the year-old model might see a reduction. It's really not that those companies "let" Apple take the digital music player market, rather Apple attacked an existing market with something much easier to use. Now Apple has attacked the Tablet market with a much easier to use product. The only difference this time is that the other manufacturers are reacting much more quickly but could end up shooting themselves in the foot if their quality doesn't match up to their pricing. The fact that Apple drastically undercut original estimates of their tablet's prices means that any competitor must either compete on quality at the same price--which they've so far failed to do--or try to undercut Apple's prices with lower-quality devices--which they've also failed to do up to now.
