Wondering these day if Bitcoin will stay decentralized forever...hear me out

The mining difficulty is rising day by day, I used to be a miner back when mining was as easy as 90mh/s and have quit half a year ago.These day you need to be way beyond the gigahash range to earn anything at all.

Most of the blocks nowadays are mined by pools, and people are simply splitting 25BTC into hundreds of thousands of tiny bits among themselves.
And we have to include the fact that the price is falling and not looking that well these days.

SO......what if the general public quits mining because it's not profitable and they can't keep up anymore?

There are a lot of mining companies around these days...what I'm saying is that Bitcoin might share the same fate as gold, diamond, etc. where there are buttloads(~240gallons ) of the thing out there waiting to be mined but large companies take control of the distribution so that they can make more profit out of it...

Some country's governments are also interested in Bitcoins such as the US and China...there are rumors about the Chinese government interested to putting their latest and the world's fastest supercomputer into Bitcoin mining. Who knows how powerful these computers are at mining Bitcoins? What if this turns into another race between countries just like the arms race and the space race? Where they compete who can mine the fastest and take control over the Bitcoin supply?

These are just some random thoughts I have sometimes......