Failure to get a single yard in a situation where you need it the most, or maybe failing to stop the opponent from picking up 20 yards when you had 4th and 19, these things aren't characteristics intrinsic to any particular coaching philosophy. It just means the team isn't that good.

We all remember VT games the last decade when Foster was still here, the opponent would put out a running QB and we'd all think oh great, here we go again, the backup running QB is about to gash VT's defense for 150+ yards. But Foster's defenses had stopped many running QBs cold in their tracks over the years too. His scheme didn't make VT uniquely vulnerable to running QBs (no moreso than any other college team), it's just the 2000s had mostly incredible defenses, and the 2010s had mostly forgettable ones.