As a counterpoint, I really hope they don't lower rates anytime soon. What the Supercharger network needs most right now is more. More stations at [some] existing locations, more locations, more CCS cables in Europe, more kW max charge rate. More doesn't come freely. Tesla is trying to be sustainably profitable, and if we want that (I do) and also for the Supercharger network to continue rapid expansion (I do), then Tesla pricing access sustainably is part and parcel.
I can see how folks would be annoyed that the rates have gone up twice pretty recently, and that some will feel that this is a betrayal of Tesla's promises. I can't say you're wrong. But as various military minds have said, no plan ever survives contact with the enemy. Not a perfect analogy here, but a useful one, IMO.
Tesla created the network to solve the chicken-egg problem of no one wanting to jump into a market with no quick refueling network, and no providers wanting to create such a network without a market existing first. They succeeded in that mission. Now they have a related but different issue--they're selling vehicles at a very impressive rate, and the Supercharger network needs to keep up with that rate of expansion. If you're annoyed that Supercharging costs are about equivalent to a gasoline hybrid vehicle, believe me when I say you'd be far more annoyed if you had to wait in line for an hour whenever you want to Supercharge.
Regardless of the somewhat muddled messaging from Tesla over time, Supercharging is for long-distance travel, and for locals who need to Supercharge because they cannot procure home or work charging sufficient to meet their needs. Full stop. If you're using it for those purposes, then the newly-inflated rates shouldn't be that disconcerting since you're either Supercharging fairly rarely or you're Supercharging in place of putting in or paying for your own home charging setup.
If you were instead planning to leech off the network just because it's cheap and you can, then I have little sympathy for you. Little rather than none because, again, Tesla has not done as good a job in communicating the Supercharger network's purpose as I'd have liked. But very close to none--at the end of the day, the success of Tesla in the general sense and of the Supercharging network specifically are far, far more important to me than the tears of a small subset of the population. That may sound harsh, but it is what it is.