That's pretty much how majority vote works. If you are out-voted you have two choices
It depends entirely on your model of democracy used. In any event, there is no way that the two strongest candidates the ANC could find were put forward. It's common knowledge that the ANCYL and COSATU and ACDP structures forced their man in there, so it doesn't really matter how the vote went, it was a farce to begin with. Strangely, the ANC's electoral structure is on a winner takes all basis, yet the democracy model on which our country runs is a proportional representation model. Odd that the former is considered perfectly democratic when it is so extremely flawed...
1. Suck it up and try again in the next elections
Who was his man? Mbeki? Mbeki wasn't going to run in another election after this anyway, so no, not an option.
2. Form your own break-away party. That way you'll be assured of being elected.
This is where you seem to harbour some agression towards Lekota. It is his right to form a political party as he wishes. The country allows him to do this. The constitution allows him to do this. Democracy and good governance encourages him to do this. Starting a political party is not all about wanting to rule.
Lekota has chosen no 2.
Shouldn't democracy mean that you accept the outcome even if it does not favour you?
What if the result was based on a farcical by-election (that really shouldn't be used to pass resolutions about the laws governing the country)? The point of a democracy is that you're accountable to the people who put you in power when elected to power, and to
keep those that were elected to power accountable for their actions - also acting in the will of the people. One could argue - successfully - that Lekota is doing exactly that.
Would he be starting this party if he was elected?
He wasn't in the running. You seem to have employed a strawman argument in your reasoning here. I shall revisit if I were you.
He has the makings of a dictator, someone who'd do anything to cling to power.
Same was said about Thabo Mbeki - he consciously and aggressively campaigned for a 3rd term as ANC leader - that would seem far more "dictatorial" than Lekota...