It is better to focus on chasing the Serie-A trophy first rather than setting a bigger target in the Champions League because we know that the Champions League is not an easy league to conquer because it requires a qualified squad depth along with a strong mentality like that built by PSG last season. Atalanta's squad is not too bad but the number of players they have is not enough to compete in the Champions League because we can see how they performed last season.
In Serie-A Atalanta have indeed made progress in the last two seasons and I think that is what needs to be improved first so that they can achieve success next season. Ivan Juric comes with a much more realistic target and maybe for the first stage he can make progress in terms of competing for the Serie-A trophy first before going further.
I agree with you that Atalanta should focus on winning Scudetto before thinking to win UCL because nobody knows when will be possible. Any club that wins UCL is already used to winning their domestic league. I don' think that a club will come from nowhere without dominating their domestic league and win UCL. It can only happen in Europa League. I hope that Juric will be able to keep the team on top four even if they don't win Scudetto next season.
Not even anything else, if they could win the league alone that would be good for them. They have been doing this for a while now, Gasperini doing a great job and he has taken Atalanta to a great level, and they even won UEL recently so we need to realize this won't be the same anymore, they can't keep playing at the same level ,they need to grow. But firing Gasperini wouldn't make sense, why would you fire the guy that took you from nothing to here.
However, they need to help Gasperini, realize this dream, give him better players, because winning Serie A would be a big deal for them. I still doubt there is even a remote chance they could win UCL, not even 1% to me, but at the same time they need to improve for the future.
Gasperini wasn't fired, he left the club for Roma after nine good years with Atalanta. He built the team to thos standard, he could have waited for two more seaaons to perfect the team performance in order for them to win Scudetto. I don't think that Atalanta will be able to catch up fast with Juric game pattern fast and that will affect their performance in the beginning of next season.