I don't see that really. Some powergaming groups may be like that, and more power to them, but I've played party bricks that have a 16 or 17 strength, and nobody laughed.
Now, thanks to point-buy we have a standard scale of how much is how much, and how powerful characters can be. If it's 25 point buy and an 18 is serious business, and you're going to be suffering in at least two scores as a result. With a 32 point buy, an 18 is what you're best at, but you can be good at something else too. WotC says that the standard is 25 points, but in most games I've seen 32 is more common.
Don't forget that dice rolling methods have changed over the years. 3d6 was a lot more standard than it is now, while now it's 4d6, drop low. The standards remain; 10 is average, 3 is practical human minimum, 18 is normal human maximum, the only changes is that PC's often start a little towards the higher end in what they are good at, and thanks to magic items and level-based improvement they can start to exceed their normal limits.
The magic item improvement is also based on a change from earlier editions. Previously, magic items would set your Strength (since few items affected other scores) to a fixed score, usually 18 or the like. For a 9 strength fighter who barely qualified for the class, he went from a marginal washout to a walking pile of destruction in a few seconds, for an 17 strength fighter, not so much. A flat bonus gives these items a fixed value.
Also, don't forget that the scale isn't as extreme at upper ends like it once was. Above 18 isn't into the realm of the godly and inhuman quite yet, just "above normal human" range, 25 doesn't mean nigh-infinite either. There isn't the wacky percentile strength either. Even in the real world, world weightlifting records are roughly in the range of what would be a 22 strength in d20 terms, so we even have real-world examples of "above 18".