That's gotta be bullshit unless you're running a 64-bit Mac. Lion killed off 32-bit support in 2011. Model, please?
Not the parent poster, but my 6 year old mid-2009 15" MBP is currently running the latest public El Capitán beta with no problems. My 2008 Mac Pro is on the current Yosemite release, as I don't run beta OSs on that machine.