People frequently seem to ask what happens to the security of the Blockchain when the mining rewards slow down if the fees aren't high enough to pay the miners.

Here's an idea;

Large scale miners slowly wind down as profits drop, smaller scale miners using renewable sources all over the world carry on mining because it's a) cheap enough and b) critical to keeping the network running.

It was never envisaged that a number of mining companies would arise as they have or would go public, with all the dodgy incentives that brings.

This isn't what was expected but for now it's what we've got. It'll change over time. We don't need high fees to keep public companies afloat. Fee's won't matter, they'll just be a nice juicy bonus.