We had bigger needs.
Part of the problem that people don't realize is that Parcells had to make a MAJOR overhaul of the offense. There's only 2 starters from the Campo offense that are still on the team (Flozell & Gurode). People don't understand that while Parcells did help coach the defense, he focused most of his efforts on the offense. Offenses usually don't get dramatically better after one season. A good offense is usually one that progressed over a few years to get to the point it is at today. Parcells probably knew that, so when he took over Dallas' awful offense he knew he it was going to take probably 3-4 years.
Also, he wanted to change to the 3-4 which means overhauling the front seven. Dexter Coakley and Dat Nguyen were good players in the old scheme, but even in their primes they wouldn't fit into a 3-4, especially Parcells' since the ILB's take on guards quite a bit.
It would've been nice to see him get a better compliment at safety sooner, but he did have a lot of other work to do. Plus, the league has shown you can get quality safeties in later rounds, even undrafted ones at times. So I can understand why it took awhile.
YAKUZA