Apple's PowerPC chipsets were always a day late and a dollar short compared to the competition. For all of PowerPC's positive attributes Apple's sheer laziness/incompetence in designing system chipsets was a constant monkey on the platform's back.
Apple used the same motherboard chipset, the one designed for the Beige G3, for three years, with only one minor tweak. (The "Heathrow" IC was replaced with "Paddington", the difference being 10mbit vs. 100mb Ethernet PHY support.) It had an ATA2 controller and no USB. (Apple gets all this credit for being an "innovator" in USB, but the first Macs with USB technically didn't have built-in support for it. They used an accessory PCI controller chip.) By comparison the early 1997 Intel PIIX3 southbridge was fully ATA3 compliant and included a USB controller (although early versions were buggy and it was often disabled.) And by 1998 Intel boards shipped with the ATA4/USB equipped PIIX4 (which by that time was usually paired with an AGP-capable Northbridge), which was an excellent chip. (It was so well supported that VMware/Virtualbox emulate it by default to this day.)
That was a tough time for Apple. In an attempt to achieve "feature parity" with standard PCs the B&W G3 shipped with an (initially buggy) accessory ATA4 controller and an "overclocked" PCI slot for video, which goes a lot to explain why it's a notoriously buggy and unreliable computer. Apparently Apple decided in the case of the Lombard they could afford to squeeze a USB controller onto what's essentially same motherboard as the "Wallstreet" but an ATA controller was too much. So they just went with the "Paddington" IDE and hoped no one would notice. The Lombard is really just a stopgap machine, just like the trayload iMacs, B&W G3, "Original" (non-AGP) iBook, and "Yikes" G4s were. The Pismo is technically the first "Jobsian"-era Mac laptop in terms of chipsets.
(Which of course is full of its own sadness, such as *never* developing a chipset supporting G4s with a DDR frontside bus.)