Wait, we're comparing Satoshi-san to Gandhi now?
Are these two struggles similar in severity, importance, or necessity? No, of course not. Do they need to be, in order to reference that quote? No, of course not.
Why is it not necessary that these two situations be equivalent, or even similar, in that respect? Because he was not saying that the effort to get bitcoin widely accepted is as important as Indian independence.
I don't agree; instead, I'd call it "an effort".
It would be "a struggle" if people were risking going to jail, or being executed, or otherwise suffering non-voluntary consequences (like losing money for having speculated in BTC) for their participation, or were somehow barred from enjoying the same benefits as everyone else because of some imposed inability to participate.
As it stands, absent other, already specifically illegal activity (like the proscribed forms of tax evasion I suspect a great many Bitcoinophiles engage in, or using their cryptolucre to buy controlled substances), the greatest risk BTC owners face is selling at a lower exchange rate than they bought at — or maybe having their wallet stolen.
IMO, to call that "a struggle" devalues the word for the other things we call struggles, like independence movements, overthrowing tyrannies, civil rights, or marriage equality.
There doesn't have to be; that quote applies to a lot more things than just the Indian independence movement.
There's also a lot of things it doesn't apply to, and its pretty much impossible to tell which things it does and does not apply to a priori. Its pretty much why the quote is stupid when uttered by anyone other than Ghandi.