The RNLI do not - cannot - pick and choose who to rescue. It is quite possible that there are crews who are angry about having to pick-up small-boat asylum seekers but they have a job to do and do it.
It is also quite possible that crews are vexed by the number of times they have to rescue holidaymakers who have ignored all the signs about prohibited beaches, dangerous mudflats, fast incoming tides etc.
They must surely be angry about the number of people who ignore the "No parking on the slipway"signs and happily leave their car there while going for a nice picnic elsewhere, preventing the RNLI and Coastguard launching.