I agree. It's never been a problem. I'm actually surprised at how often I hear someone say they're "competing" for the same space. I wonder if people are determining this with their eyes or their ears.
Let's not forget that no two kick drums are the same, nor are any two bass recordings. Kick drums vary in diameter, skin composition, beater composition and tuning. Bass can be 5-string, 6-string, played only on the first three frets or up in no-man's land, DI'd or miked.
Sometimes the problem isn't even with the instruments or the recordings, it's with the monitoring. When your room is nulling certain bass frequencies at your listening position, it's doing so to both the bass and the kick, which tends to leave them sounding pretty much the same.
And finally, sometimes people mix with their ears, but their ears (read: their brain) tends to favor a certain sound as "awsome", and tried to get both the kick and the bass to have that same "awsome" punch, and they wind up sounding the same.
I concur with Ford's sidechain idea as a nice blanket solution for most of that. It's a tried-and-true go-to. I'd also add that - for next time - looking closely and objectively at each of the above factors and taking the opportunity to try and get them right at the source - i.e. select/tune the kick to cooperate with the bass arrangement, don't try forcing the kick and the bass to compete just because you like a frequency, but let them find their own sonic territories, make sure the problem is real and not just a product of your monitoring, etc. - and you might find yourself even more pleased with the overall results.
G.