It is by no means insane, especially if you consider the broader legal status. It's illegal to break into places, and it's illegal to occupy people's homes. What is called squatting refers to occupying empty/abandoned places, and it would be insane to make that a criminal offense.
There is subtlety here. Leaving it empty because you are away doesn't mean it's not your residence anymore. Abandoning it changes the legal status of its occupation. Only abandoning the place makes squatting not a criminal offense in most countries.
Such difference exists for a reason, as a balance against an absolute power of owners which drives the number of homeless people up as we can see in certain areas. Take for example the netherlands. It was very common and well regarded to squat for a while, and the homeless population was very low. Now that squatting has been outlawed, both homeless and empty dwellings have gone up. There was some public study on the topic a while back: https://en.squat.net/2016/05/27/netherlands-housing-crisis/
Leaving your primary home empty because you visited a grocery store is not the same as leaving your 2nd (physically unnecessary) home empty except for 4 weeks a summer.
UK squatters generally move into buildings the local community consider to be blighted, so there’s never much of an outrage. As an owner it’d be hard to claim damages against a building that was a tear-down thirty years ago.
In this case the property was closed sometime in mid-March [0] and the police were made aware of the squatters on 4/10. That's less than one month empty before the squatters took possession.
Now that the squatters are there and apparently can only be dealt with through a civil lawsuit, the odds of someone wanting to buy the property are presumably much lower, so it's going to remain abandoned and unused for much longer than it otherwise would. How is that a favorable outcome for the community?
Assuming you are commenting in good faith, no of course not your empty bedroom. A person's residence is protected by law in most countries, and this has nothing to do with the legal status of squatting.
Occupying part of someone's residence while they are there, or while they are away is strongly illegal and criminal, a violation of the residence. Nothing to do with squatting: this practice of stealing people's homes does not exist (or very anecdotally) and is dealt with by the police without trial in every country.
You can for example study the mediatic cases brought forward by the french far-right media (BFM TV / CNEWS) such as the Maryvonne case or the Roland case: they have not been acted upon by the police because they were abandoned houses that were not the residence of the owners despite what they claimed in the media.
