Let me pose a challenge then. How many valid anecdotes can you point to? These must have two, post-peak serum testosterone measurements that demonstrate unusually low apparent half-lives for the esters.
The more plausible alternative is that the anecdotes consist of low-SHBG guys posting trough total testosterone measurements that seem relatively low for the dose. So the assumption is made, incorrectly, that the peak is normal and the drop in levels is faster. Thus a myth is born. But instead, it is expected that when all else is equal, the low-SHBG guy has lower total testosterone throughout the injection cycle, and the apparent half-life of the ester is no different than what the high-SHBG guy sees.