It sounds like you're dismissing the innovations around bitcoin over a broader grievance against speculation.
A few more points on this:
1) They risked their money. I agree that sometimes a very high return seems unfair/unwarranted (again, true of speculation in general).
2) Many people holding a lot of bitcoin (e.g. the Winklevii) are working very hard towards bitcoin's success. They believe in the technology. If that turns them into billionaires, I don't see that as any more unreasonable than Facebook billionaires. Aside from those who are working hard, with any technology/startup there are usually some "passive" investors that hit pay dirt. Would you cap Mark Zuckerberg's upside since there must have been some people invested in, or employed by, Facebook that really didn't do anything, yet made quite a bit of money? Who's going to decide what's reasonable?
3) Let the market decide. There are competing alternatives, let's see what happens. If enough people are outraged by the thought of a few bitcoin speculators making billions, then perhaps that could kill it. I'm guessing that kind of broad dislike for speculators would lead to less speculative ventures, which doesn't sound good for innovation.
Not true. Miners helped secure the network (and were rewarded with more bitcoins for doing so due to the mining difficulty) when bitcoin was brand new and vulnerable to attacks. It sounds like you haven't read much about how bitcoin works.
There is some value in it, however as I stated, these people really didn't do anything to warrant the unreasonable amount of gain they have or will have. A better system can exist where this unreasonable distribution doesn't occur. Bitcoin in its current form isn't the only possible version, so why not compare it and break it down into "oh, well there is high adoption so there's enough value that we should look the other way and ignore better ways where value is even higher for even more people - or even everyone."