I'm not the biggest fan of the 99 percent slogan tbh its led to a lot of confusion about how to relate to the police and glosses over a lot of stratification, race, and gender stuff. A boss, pig, or landlord who's income may put them in the 99% demographic has an entirely different relationship to the system than marginalized workers in precarious service jobs, youth/people of color, single mom working a bunch of retail jobs, the unemployed, etc.
Yeah, I'm sure someone in the top 2% likes the irony of technically still being in the 99%, but I don't think that's the biggest deal here because nobody's framing the protest in such a way. What the protesters want to show is that it's not just poor or uneducated people whose lives are crummy but also people who you wouldn't expect, like those who graduated university, or people who had successful jobs or businesses and now declare bankruptcy because of an illness. It's not just a few unlucky suckers at the bottom—it's a deeply systemic problem that affects a very great deal of people.
So yeah, technically 99% is not an accurate description and you're right to point that out, but it's not the biggest problem I have with it. And frankly, even though "we are the 99%" is the most common payoff, I don't think many of the common folks watching this protest unfold are aware of the issues you raise. It's a legitimate complaint but I doubt it's responsible for so much confusion.
It's imperative to judge the quality of protests because their goal is to show people who are uneducated on a particular issue why they should support their side of it. The "I am the 99%" campaign is not very effective at this.
Yes, but it's not very clever to go and call people idiots because you don't like their protest signs. Or even if you don't like their protest. I don't think the Tea Party folks were idiots. Extremely misguided and actively working against their own interests, yes, but they were still just regular people with legitimate economic complaints. They're part of the proverbial "99%". The first question you should ask yourself is whether the protest is legitimate. I don't know what signs you saw but the "I want to buy a useless gadget but I can't, I am the 99%" crowd you're talking about is completely unknown to me.