NJ...while what you say is strictly true, its completely unrealistic to think that people will be going in to the Polling Booth with a fervent wish to elect their local MP, and not to elect the next Government. The vast majority of voters aren't even aware of who their local MP is, unless he or she is high profile. I can remember a time when the Party of each candidate wasn't even on the Ballot Papers, just the name of the candidate. ( Not sure when that changed though ? )
If the electorate end up giving both Labour and the Tories about the same number of MPs, then a coalition of some kind is inevitable. Its what happens in many other European countries, mostly due to the huge number of slightly different Parties that are available to vote for, and that is how democracy works !
So, until we reach a time when most of the minor Parties, like UKIP, The Greens, Plaid Cymru, etc, etc disappear, we must accept that we faced with coalitions into the foreseeable future.
I don't like it any more than you do, but when the People speak, we have no choice but to listen !