Dang, you caught me!
Seriously, it's more a sign of the times that it's sometimes necessary to provided the "clean gain warning". Any decent pre amp should be able to provide sufficient clean gain. However, there are enough cheapies out there that, while the provide sufficient gain, get noisy if you try to actually USE that gain. I'm looking at you, Uli Behringer and your ADA8000 boxes (and many of the cheap mixers too). A good hint about the ones that do this is that, on their gain spec, they don't post a noise figure BTW.
Anyhow, as long as it's clean, 60dB of gain is plenty for the SM7B.
BTW, for hand held, you've probably rediscovered the inverse square law. I'll wager that in HH mode, you're working a lot closer to the mic than in the studio. If you move the same sound source from 8 inches away to 4 inches away, you need 6dB less gain. If you move from 4 inches to 2 inches, it's another 6 dB off the gain you need. Also, if you're talking live, adrenalin always tends to cause vocalists to be a lot louder. Between dress rehearsals and actual performances in the theatre, I notice a lot of actors get about 1odB louder as they project more. Makes setting gain interesting!