[Locke]

So they already built super powered suits once and now they can't replicate that at all and just use a different power source...right...

Even if we don't concentrate on Boukenger, there are still tons of other cameos that defy all reason and logic. You had that MagiRed fella with Flaggle showing he still had powers, but he's too busy stood around in a towel trying to look mysterious. You have GekiRed, the master martial artist as to what I am guessing is super human levels...bumming about. And even though the Power Lion exists to defend the planet, is still alive, as is his master is he trying to help fight off the invasion? LOL NOPE.

It isn't even like it makes sense within its own story, someone said something silly like 'well the Rangers trust the Gokaiger to get the job done' or some shit, like okay? So that means the Rangers just sit on their hands?

Well clearly not as you see the Goseiger and Gingaman Rangers still want to fight, you see the Deka Police people still doing their jobs, you still see GoGo Pink helping people. So all the cameos that feature passive Rangers taking up knitting or whatever they are doing while an invasion is literally happening around them is beyond the parameters of stupid.