Spain and France are both on the ‘not safe to travel to’ list now. The total cumulative number of cases is irrelevant - what is being measured now is the cases per 100k people over a two week period.
Italy right now has only 12 cases per 100k people over the last 14 days, nearly half the infection rate of the UK.
So yes, absolutely inadvisable to travel to one of the countries on the ‘quarantine’ list. Italy and Greece are not on that list and have been deemed safe to travel to, so again I say why not?
The risk is no higher than using public transport in the UK, or going to a bar or restaurant here.
And you’re missing the point - UK travel businesses and airlines are under massive threat right now. Some have already gone out of business, and thousands of jobs have already been lost. Those people affected ARE ‘in our own country’ and are struggling - or do you not think they deserve support?