I think people use these tools quite a lot here, especially for situations exactly like you describe. So to answer a portion of you question, I don't think it's taboo. That said, I personally prefer manually going through my recordings and fading the quieter sections and use the gain tool to get the levels where I want them. I feel like I have more control of the end result that way and how I want it to sound, because I usually do still want the quiet sections to sound quiet, but they need to be loud enough that I'm not reaching for the volume control during playback if that makes sense.