But ultimately it's not ideal to have unknown people entering your country illegally
For the majority of people this is the only way they can present themselves to claim aslyum. Until that changes (for which there is little political will), making it harder to enter the UK without permission will only extend the plight of those fleeing conflict and persecution etc.
Not sure this is a bad joke but there are plenty of reasons why people have a valid right to claim aslyum in the UK and why that would be preferential to them than claiming it in France.
For the majority of people this is the only way they can present themselves to claim aslyum. Until that changes (for which there is little political will), making it harder to enter the UK without permission will only extend the plight of those fleeing conflict and persecution etc.