Boris Johnson was born in the US. If he commits violent crime in the UK should he be stripped of his British citizenship and deported there? He has renounced his US citizenship. How can the UK force the US to admit him?
But the Shamima Begum reference is telling because she was born in the UK to British citizen parents. So you're not just about deporting people born outside the UK, you're about deporting anyone who may have foreign ancestry.
You haven't really thought this true to any extent, have you? But that's okay because it doesn't affect you and your family, does it? Here's an idea, if you want to start applying different rules to British citizens based on their ancestry, let's have a rule where we don't have to pay the escalating benefits for an idle and feckless native population who demand more and more welfare benefits all the time? You see, once you start dividing up the population on ancestry it's not just something that will get applied against the "others" - the "others" will start to apply it to you also. White British children have, statistically, the lowest educational achievement of any ethnic group - maybe it's time that group started to be taxed more to fund remedial education for them.