686B bug, PCI Latency issues, USB renumeration problems, etc.
For some things VIA boards work great. For others, they can be a nightmare of little issues that never quite get sorted out. Though VIA has supposedly issued fixes for the above problems, they don't always work in every case. My system is now about 95% stable, but some things, like video production/encoding of multi-gigabyte files can send it into a spin.
His remark was sweeping and generalized, but not entirely incorrect. There are more pampering issues to deal with for VIA chipsets. Just look around here for how many little problems people have that are just flakiness issues.