If you look how often (even here) people complain that the origins of the resistance and the first order aren’t explained sufficiently, you can imagine what people would be saying without these exposition scenes.
I don’t understand what you mean: not telling (or not explaining enough) it’s different from telling (through expositions) or not telling directly (through symbolism).
I guess those people would like to know more about the background, but they shouldn’t complain: LF just decided to not tell about their origins, probably because they felt it wasn’t needed to understand the plot or the characters, that it could’ve even confused the viewers with too many informations.
On the other hand, to me one thing they should’ve explained better was the relationship between the Republic and the Resistence, because it makes the main characters’ involvement in the plot itself not clear: are they the fighting with the Republic? Are they supported by the Republic? Are they unofficially supported by the Republic? Are they rogues? Since not even Rey or Finn (the viewers) knew about the Resistence, I thought this would’ve just been explained later in the movie, but it didn’t happen, as far as I remember.