I feel like you're trying to be clever here as indentation is also a sort of alignment

That's what I said.

Thus spaces are used for indentation and spaces for alignment.

Did you mean what you just said? I think you mean, tabs are used to indent, and spaces are used to align the =.

Still, now you have to enter a space in for every space between $user and =. Rather than just hit tab once. Granted, you could repeat that so you don't actually have to type in all those spaces, but then you can also jump around spaces as well. I mean, the way you are describing this, the only benefit tabs have now is in terms of being able to set the tab width to be whatever you want it to be. However, the problem is, if a tab is used between $user and = true, it screws everything up.

So, you have to force a tabs on the left, spaces to the right approach. That's rarely what happens in practice. However, this is aptly named tabs for indentation, spaces for alignment.

Anyways, my assertion was never that tabs were bad (though I prefer spaces). Rather, that suggesting that tabs are easier when editing isn't an issue with spaces as much as it's a failure in the editor that you are using. Good editors, like vi (not only vi, for some reason, people seem to think I'm only arguing for vi and spaces here), don't have this issue.