Governments are ultimately just a majority of MPs.
All those government decisions you disagreed with as a youth were voted through by a load of MPs, most of whom were a bunch of vapid nonentities voted in by huge majorities just as they are today and just as they were 50 years before.
Any time the government of the day has been in power for 10 years or more they run out of MPs who can reasonably be ministers. Whoever's in power.
The quality of MPs has not, in general, been in consistent decline for the last 60 years. Regardless of the quality of any given parliament.
To be fair on this specific point, I do think governments should be able to appoint ministers from outside the commons if the most competent and appropriate candidate isn't an MP for any reason.