They didn't have Google Maps then.

Also, it seems unlikely that the current or future government of England will actively try and erase him from history again.

One...

And that's it. Remember a lot of politicians are/were lawyers. But seriously, the only downside is that it might encourage companies to keep things as trade secret so that they don't have to publicize it.

And that would appear to be what they are doing. Also, patents aren't trademarks. You don't lose them if you don't sue.

It is not the patent holders responsibility to publicize their patents. It is the responsibility of any inventor to do a patent search first to understand the patent landscape and determine where they have freedom to operate.

Ignorance is not a defense in the eyes of the law.

How you can list terrible IBM software and NOT mention Lotus Notes is, frankly, shocking.