My argument was that it is impossible to exclude SPJ from any sensible definition of "theoretical computer science", unless you are taking those words and re-defining them to mean something other than what they actually mean as a collection of words.
I accept that there may be a group of people who call what they do "theoretical computer science", and who believe that nothing else is "theoretical computer science", but in that case, the onus is on those people to remember to translate "theoretical computer science" as a term into "complexity theory" when they talk to people outside the complexity theory community, because the rest of us have a much stronger claim to the general meaning of the term, which encompasses both this idiosyncratic use of "TCS" as well as all of the other things that it can correctly be taken to mean.
Allow me to make my argument entirely concrete:
Let's say that I do "organic chemistry" and I go to organic chemistry conferences with other organic chemists. Obviously there are other sub-branches of chemistry. If I decided to stop calling what I do "organic chemistry" and start calling it just "chemistry" instead, to the exclusion of any other kind of chemistry, you can understand why people would be very confused (and probably a little annoyed) when I start telling them that Alfred Nobel wasn't a chemist.
I will go even further to say that the test for a sensible definition of "theoretical computer science" is probably which people it includes, and SPJ would probably be on that list, IMHO (along with Hoare and Milner and countless others who are excluded by this supposedly widely-held definition).
And I really don't think it's widely-held outside of the community that calls itself the TCS community, which by definition, doesn't make it a "widely held view", does it?