One is an internal challenge (WE are unhappy.) the other is an external challenge (THEY are unhappy.). Tories give no ***** about other people, but will always rally around their own in case of challenge.
One of the architects of Brexit (and the original negotiator) says Brexit is failing as it’s a “remainers’ Brexit”. To these people, it’ll never be Brexit enough as long as the UK has any treaties with the EU and all the foreigners haven’t been deported.