WWI is so far in the distance that you can make real life political figures fun Easter Eggs. "That's Hitler- he's more important in the sequels!"
'Imperialism bad, but it is super tempting' is genuinely the main theme of the film. As a WWI moron :whywhywhywhywhy: -Please tell me why the film's bad
Its more then that even...its also a sort of passing of the torch/commentary on the transition of the spy genre from Sean Connery's Bond to Daniel Craig (or even Jason Bourne for that matter).
The point of the movie is basically a buddy film about the old school well groomed British gentleman era spy played by Collin Firth getting to train and work with the grittier more grounded and working class operator/commando agent build played by Taron Egerton. Both types of spies would objectify women and get the girl in the end...but Eggsy is unbred and uncouth and thus he gets anal.
Gross and problematic? Definitely. There was a thought behind it though.