I don't think they are bullshit, as a user of the latest firefox that ships with Ubuntu I see this all the time:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
23974 rgr 20 0 2656m 1.8g 40m S 55 23.3 164:03.18 firefox
It's a great laptop with 8 GB of RAM, 4 cores, etc. Still, I often restart firefox just to get work done.
The state of the browser world is pretty shabby right now. Basically, the browser is replacing the desktop window manager as a key piece of software - between webmail (gmail), web-based time tracking (harvest), keeping notes in an internal wiki, etc, much of my work is done in a browser. The state of that browser world is basically like the desktop world about 1995: the easiest solutions to use are filled with other people's programs running on my resources to their ends (usually advertising), the most private and ethical solutions lack the capability to do many things (in 1995 it was run specific programs, now it is use specific websites).
I don't see much hope from the web development and browser communities. When you talk to anyone in those communities and ask an open ended question such as "what's the biggest problem we're facing" or "what most excites you about the industry today" the response is usually about web standards, java script, and bastardizing page description into a bad programming language, making websites less ugly on mobile devices.
That your computer does what you want it to, instead of merely generating heat, or even worse yet computing flashy ads you don't want to see and collecting information for your enemies, isn't on their radar except as a knee-jerk platitude or afterthought. "Oh yeah, and privacy. We only write websites that don't track you if you put your name on a list."
So it is not a surprise that the browser they produce barely runs on the kinds of computers the top few percent of the world can afford, and that it collects information for the top 0.01 percent.
Perhaps if much of the world starts using tiny computers based on the new cheap system-on-a-chip ARM stuff, like the Raspberry PI and Beagleboard Bone and etc, there will be a brief opening where there is no good browser available for those machines and a new one could make headway. But I think we'd end up back in the same place on that platform for the same reasons unless we do something differently.