The reason you don't hear it get brought up very often is because it's only happened 5 times in U.S. history, and the first three occurred in the 1800s. The other two are the aforementioned 2000 election of Bush v Gore, and the 2016 election of Clinton v Trump.
And California having a lot of electoral votes does nothing to diminish the effects of other states' votes. California is only ~8% of the total population of the U.S. 8% is a lot, but it's not going to win you the election by itself. In fact, if basing the electoral college on population, California would lose some of their electoral votes because they have over 10% of electoral votes.
Plus, it's not just Republican states that have small voter to votes ratios. Hawaii votes Democrat routinely, but it gets 3 votes with less than 1.5 million people living there. Again, 500,000 votes per electoral vote compared to California's 700,000 votes per electoral vote.
Besides, let's look at it this way. If the electoral college reflected population, then why not just use the popular vote?
And this is part of the problem. The only way the electoral college means anything is if it doesn't reflect the popular vote. Yet if the majority of the country prefers one candidate over another, and the other candidate wins the election through the electoral college, how can you call it a democratic election? The basis of democracy is that majority rules, yet the electoral college can throw all that out the window.
Part of it is that the electoral college is a winner takes all system, so a close race in a state translates to a landslide for the winner. If you win a state 50.1% to 49.9%, you don't get 50.1% or even 60% of their votes, but 100% of their votes. But is that fair to the 49.9% who didn't vote for you? Their vote is essentially tossed out because they didn't win.
In general, the electoral college has always been a mess. The reason it's never brought up though is because, for most intents and purposes, it will reflect the popular vote. It's the fringe cases that show the problems with the system.