I will try to answer this as objectively as I can to show how they got into that position.

• <10% of registered voters actually voted in the primaries, compared to ~60% who will likely vote in the actual Election

• This means only a very small amount of people actually voted in either candidate. Voter apathy, especially in non-presidential elections, is the biggest issue here. Let's say 20%+ of voters instead actually educated themselves regarding all candidates involved and put in effort into voting for the right candidate in their eyes, and there is a good chance we wouldn't be faced with either of Trump or Clinton

• Clinton relied on two things: time essentially running out, and a major bias within the DNC(this is well known due to the email leaks). It was obvious each day, week, and month that passed, Sanders' stock was growing while Clinton's was falling. Sanders came on too late for enough people to really get to hear about him while Clinton is one of the biggest names in the country

• Trump relied on having the personality and ability to spark voters to be able to stand out in a very crowded field of candidates. The RNC really hurt themselves by having so many candidates to choose from.

• Combine all that with voters being extremely limited with their votes within a two party system, and this is what we get

That's pretty much how two incredibly unfavorable candidates are now the two main candidates to be elected for President. It's a sad reality.