Why should I vote if the electoral college votes are the only votes that count?

Because your vote is how the Electors are elected. The process is described in the Constitution.

Electoral College votes are determined by the popular vote. In 48 states, plus Washington DC, whoever wins the popular vote in the state wins all of that state's electoral votes. In Nebraska and Maine the electoral votes are apportioned based on the percentage of the popular vote that a candidate wins. In almost all case in American history, the winner of the electoral vote has also been the winner of the popular vote. There have only been a handful of cases like what happened in 2000 where the more popular candidate ended up getting less of the electoral vote and thus losing the race. The Electoral College can sometimes magnify a candidate's apparent victory (for example, in 1980, Ronald Reagan won less than 51% of the popular vote but carried all but six states), but they very very rarely fail to ratify the will of the people.

Should be the popular vote that picks the winners

US voters elect presidential electors in "electoral college". The electors then votes for president. The "electoral votes", but not "one person one vote", decides who is the US president. Otherwise, George Bush would not have won. US presidential election has fair and equitable participation right, but do not have “one person one vote” right of electing president.

You shouldn't.

Let people who actually have brain cells vote.

There is no electoral college vote without your vote. Why are you even here?

Because your vote determines the electoral college vote. Doesn't ANYONE pay attention in social studies class? Your state's electoral college delegates will cast their votes the way the votes from the public were in the election.