Within this forum in other places there are references to the importance of learning your craft, and in particular, training your ears, so that you have a better chance of producing good quality results. When you are new to recording, you may miss out on hearing things that the more seasoned engineer can pick out.
I think the same applies when you are starting off in a band: you get together, play songs, and, from your perspective of innocence and inexperience, think it sounds great. Someone else may have a contrary view: they might notice timing changes, pitch problems, poor tuning, overplaying, sloppy playing, cluttered arrangements and so on.
When you, as a band, record this stuff, it is highly likely that you will still think its good. Firstly because you won't necessarily know that it could sound better, but secondly, because you are not hearing what's there, you are hearing what you want to hear.
I've done this many times myself; recorded a track and thought 'wow, that's sounding great', but a couple of weeks (maybe months) later you listen and think 'how on earth did I think that was acceptable?'
This makes life for you as an engineer difficult, because even if you diplomatically and constructively point to various things that could improve, the client's perceptions and their 'subconcious acoustic refining' may be a barrier to their hearing what you are trying to say.