In practice, an election could enable a 'do-over', with no substantial political poison (well, no more than politicians already deal with.)
If, in an election campaign, you have two leading camps - one supporting 'Remain' and the other 'Exit' then whoever wins will be able to claim a mandate to pursue their declared preference ... and they will have the political numbers to follow through.
The thing is, the EU, and the member countries, DON'T want to interfere with an internal/national UK wide general election. Which is a good thing, so we can decide amongst ourselves, which party and hence leader, we want to take us forward.
Mixing remain/leave into the mixture, messes things up.
E.g. If Conservatives go for Leave, and Labour go for remain, ignoring other parties for now.
If the EU and/or other EU countries decides to try and put its case forward, to try and swing the 52%:48%, the other way. It could mean we get pressed into choosing a party and hence new prime minister, more based on remain/leave rather than choosing the best one for leading us and running the country for the next 5 years.
E.g. Say UKip are the only ones who go for leave, the others go for remain and/or a second referendum. We could end up getting a new prime minister who may not be the primary choice, if given a "normal" election (free of any Brexit stuff).
This Brexit sort of messes things up (muddies the waters), so maybe is NOT the best "cloud" under which to have a general election.
Also I'm surprised Boris Johnson has pulled out. But he did seem to suddenly go VERY quiet, immediately after the "Brexit" result was announced. So I'm not that surprised on reflection.