[throwawaykf1]

It's not "ambiguity of English" -- all (usefulsoftware does have a technical effect. Or would you say software should be excluded from the "tech industry" and people should stop calling themselves "software engineers"? This is why it is mostly patentable in the EU.

About the only thing the "technical effect" limitation prevents is business method patents.

[polymatter]

I don't know the rules in detail, but the claim is that "software isn't patentable". And yet software with a technical effect is patentable. But all software has a technical effect. Ergo, software isn't patentable because its software, its patentable because it has a technical effect and UKIPO has granted patents on software on that basis. This means that claiming "software isn't patentable" is a misleading claim at best.