The Republicans have won the popular vote twice in the last 30 years.
Also, you should check your facts.
Why are you cherry-picking 30 years? Why not 40 or 50? Is it because Nixon won twice? Reagan won twice?
The reason why people tend to put more emphasis on the republicans loss over the past 30 years (as opposed to the past 40/50 years) is because of the way politics has evolved.
First of all, the political environment has become much more static since the days of Bush Sr., with most states firmly entrenched in their political camps.... Carter won texas, Ford won California, Reagan won new york, Clinton won multiple deep-south states, etc. But since 2000, most states have become firm in their voting patterns.... Republicans always win texas, the deep south, and most interior states, Democrats win NY, California, etc. There are very few swing states. This appears to be a new development, and it does not appear to be changing.
Secondly, the republican party have become a group of ass-hats, between dirty election tricks (gerrymandering congressional districts, widespread voter suppression, etc.) and the breaking of political norms (such as the use of obstructionism). Back in the 70s, the republicans had enough integrity to play a role in forcing Nixon out of office. Now, in the 21st century, Trump has engaged in more unethical behavior than Nixon ever did, and the republicans continue to line up behind him. And those are the people that are deciding on judges, who will have an influence on how people live for decades to come.
Lastly, we pay more attention to what has happened in the past 30 years
because it appears to be the trend. If you have centuries of relatively stable "winner of the popular vote usually also wins the electoral college", and then within a few decades have a system where the republicans regularly fail to win the popular vote but still end up in power, people are right to question it.
If I show up at the hospital emergency room gushing blood through an open wound, the question the doctors are going to be primarly concerned with what happened post-injury. They are not going to say "There is nothing to worry about because you lived for decades before that injury".