Earlier quoted context omitted.
> You're literally restating the tactic, as if that countermands the truth The truth is the current system stabilizes at two parties due to how the rules are written, and that most voters are de facto disenfranchised at the federal (and, largely, state as well) level for a bunch of reasons. Spending any time or energy getting worked up at someone (uselessly) voting one way to try to work within that system for change…
>Spending any time or energy getting worked up at someone (uselessly) voting one way... is counterproductive. No, it's really not, because there is no alternative: the voters are the ones who have the ultimate power and responsibility here. This isn't China where the Party controls everything. >An effective use of one's time is working at the party level (by which, yes, I mean the two that get elected, not the rest)…
Popular candidates are the ones that get elected. By definition. So yes, trying to push forward better candidates supported by a party the support of which will automatically raise their profile is the way to fix the problem. Plus, as noted, voting for the changes you want (including reforming voting & districting, if that's your thing) at levels closer to home, where non-big-two candidates or oddballs within the big two might actually win.
How have we reformed elections in the past, against the wishes of entrenched, powerful groups? Replace or win over one of the big two parties (the latter is easier—the former's rarely worked) and push your candidates forward. The Democrats have a strong incentive right now to get rid of gerrymandering, for instance. There are local and state level movements to reform voting—it's mostly a state-level issue—so try to get some initiatives on the ballot. Work with that. One step at a time. Voting Green or Libertarian or whatever for President or Senator's simply pointless, good feels aside—though only barely more pointless than any other vote for a federal office, under the current system. It just doesn't matter.
Feel good, or get something done? For the former, keep on voting however you like. For the latter, work to change the ballot. Initiatives/referendums and influencing candidate selection in the big two. You can try other stuff, but those are the first things you should look at if you're serious about getting things done.
The basic principles are 1) the earlier you're involved in the process (e.g. influencing who's running, what's on the ballot) the more effective you're likely to be, 2) the more you're swimming downstream the better (if you can work in one of the big two, 100% you should), and 3) the smaller scale the election, the more likely you can affect the outcome (obviously).