Complex sentence: Mr. Woltz was greatly admired by loyal SysOps, but was known for being somewhat stubborn and due to his unwillingness to add Internet connectivity to the software SPITFIRE's usage dwindled significantly throughout the United States.
Split into simpler sentences: Mr. Woltz was greatly admired by loyal Sysops, but was known for being somewhat stubborn. Due to his unwillingness to "change with the times" (ie. add Internet connectivity to the software) Spitfire's usage dwindled significantly throughout the United States.