Agreed; how much is a lot? The right answer is "it depends", as always.
People doing nature recording want to have a lot of gain, in order to capture minute sounds. They often have to use dynamic mics, for their robustness, so they need a lot of gain. With 80 dB gain , the dynamic range cannot excess about 48 dB; taking into account some necessary headroom, it results in about 40dB effective S/N ratio - that's about the S/N ratio of a cassette recorder without Dolby. So that's about the limit for acceptable results.
For classical music, recording with distant mics, 60 dB gain is about the maximum, resulting in 60dB effective S/N ratio in the soft sections. Again, it seems to be the acceptable limit considering the typically high expectations of classical music lover.
For rock/jazz/blues/pop/country, the use of close_micing significantly changes the gain requirements. I would say that in 99% of the cases, the gain is comprized between 20 and 50 dB. In fact I reckon I could use a 35 dB fixed-gain mic pre 9 times out of 10. That is, indeed, using digital recording. If I had to print to tape, I would really need the 30 dB range of adjustment.
