You’re stretching my memory now. Although Drake was known for building some nice gear, I think I remember hearing rumblings about lemons in the R7/TR7 line, and it was a major evolution from their earlier lines - but a neighbor of mine ran a RTTY mailbox on a TR7 (and an AppleII computer) for almost 20 years, and that’s hard duty. The rig sat on his top shelf and just worked.
As I recall, most amateur radio and SWL equipment at the time (like guitar amplifiers and Russian MIGs) used extremely conservative technology; and the R7 was one of the first units to use digital circuitry. My theory is that the company didn't have any experience with digital stuff and didn't know how to deal with it.