On the one hand, I'm majorly annoyed Portugal was dropped - I was ready to book flights to the Azores on Thursday last week
However...
The data for Malta refers to the resident population of Malta at the effective start of the season. If Joe Bloggs flies from the UK to Malta, he will likely spend time in shops, cafe, bars, etc in close-ish proximity to tourists from other countries as well. Infection rate in much of northern Europe (France, Germany, etc) are significantly higher than the UK. There is zero chance of people on holiday staying 2m apart from other tourists all the time - that doesn't even happen in my local supermarket where almost everyone is stone cold sober. The owner of a struggling restaurant who has seen business decimated in the last 12 months has a choice "squeeze people and tables together a bit, or go bankrupt" - I know what I would do, especially if local Govt regulations or enforcement wasn't too strict. Infection is going to spread between tourists in resort bars - whether we like it or not
The actions of the UK Govt seem to be highly unpredictable - but an effective "no foreign travel" policy will minimise infection rates in the UK
My guess is that UK Govt policy might start to liberalise in about November (assuming no 3rd wave) by the time the warm weather is over