That is an disingenuous representation of how the attacks works. That attacks OPSEC, not the Bitlocker itself. Any full-disk encryption is "vulnerable", to this kind of attack.
Not really. Full disk encryption using Pointsec/other commercial offerings, or as you typically do it on Linux with LUKS+dmcrypt, asks for the passphrase before the OS has loaded any Firewire drivers. In which case a fully shut-down computer is not vulnerable to this attack, ie. you have protection against evil maids, thieves, FBI etc.
But with Bitlocker, it only requires a password at Windows login, and by then all the Firewire etc. drivers are up and running. So you have no protection for computers that are stolen/seized by law enforcement.
IIRC BitLocker with pre-boot authentication mitigates DMA attacks. Most Windows hardware doesn't come with FireWire or Thunderbolt ports nowadays. Microsoft recommends pre-boot auth for devices with DMA ports.
These are fair points. But for businesses in particular, it's a problem since many skip on (or are unaware of the need for) pre-boot auth, and business laptops still pack FW ports, if not on the laptop itself, then surely on the docking station.
But with Bitlocker, it only requires a password at Windows login, and by then all the Firewire etc. drivers are up and running. So you have no protection for computers that are stolen/seized by law enforcement.