While we are on the topic of "Learn it by ear", here's what I want to know: How old and how simple is the stuff you are learning by ear? Are you learning ancient standards that people have heard a million times, with pretty straight forward lines on recordings where it is easy to hear bass?
When you can pump out some Mudvayne, Obscura, Nile, Black Crown Initiate, Karnivool, Ne Obliviscaris, or Decrepit Birth out without the benefit of tabs, we'll talk.
The fact that some forms of music mixes and obscures the bass in recordings is a separate issue entirely. Obviously you cannot recreate by ear what you cannot hear in the first place. But people can hear and recite some very complex things. How complex becomes a function of a person's working memory.
So if you have to learn to play something that cannot be heard we are back to debating reading tabs vs. reading standard notation.
Standard notation wins every time as a better form of communication. It contains more useful information in the same amount of space on the page and if you can sight read you need not even hear the recording first.
Tabs has a place in the learning curve of some students, but it is something like training wheels on a bicycle. You want to move past it and go on without it at some point.