Yeah, because they’re lazy, and/or don’t have the ability to wage a sustained campaign. That’s the vast majority of voters on both sides–myself included, sadly, though in my case it’s largely because I’m afraid that a furry getting involved in a campaign would do more harm than good. Did you think every (or even a majority) of single-issue pro-birth voters were on the picket lines? Hell no. Most voters cast a vote, maybe in the primary (but usually just the general election, and only in the presidential elections) and that’s pretty much it.
And for the record, I absolutely don’t hate leftists, I agree with the vast majority of leftist positions, and I think protesting and advocating like this is a critical part of creating change. I just feel like it’s just as important to practice harm reduction and push from the inside, too.