Its the democratic nightmare: some party uses its temporary mandate to strap the electoral chicken so that only it is allowed to govern. And it has just happened in the UK, with the Tories ramming through a change to Standing Orders to ensure "English votes for English laws".
How is this strapping the electoral chicken? As I pointed out earlier in the year, by allowing only English MPs to determine English law, it effectively grants them a veto on government. In order to govern and enact their policies, future governments won't just have to have a majority in the House of Commons, but also a majority of English MPs therein. Which, given the Tory dominance of England, effectively means only they can govern in practice. A future UK Labour government (or coalition with the SNP) will face having its English policies - which means education, health, welfare and tax rates - voted down by the English Tory minority, despite having a majority in the House.
(The core problem here is the UK's devolution not having gone far enough, and Westminster still thinking that it is the legislature for England rather than the UK as a whole)
The message to the Scots is clear - despite supposedly being part of the UK, they're not going to be allowed to have any say in its government. They're peons, not citizens. And faced with that attitude, there's really only one self-respecting choice: hold another independence referendum, and leave.