I think you're pulling too many hairstrings over the "Streetcar vs LRT" nomenclature.
The poster is clearly referring to the difference in running the LRT using ATO vs on street operation, in which case this is a very valid problem. There are very few, if any, instances of ATO being used on LRTs around the world, nevermind LRTs that have to swap from ATO to regular manual operations in between stations like Eglinton needs to do. To say that the tech behind this are complicated is an understatement to say the least. In layman's terms, the Eglinton LRVs need to be able to switch from operating like a metro to operating like a tram, while at speed. It can't be understanded just how complicated that is from a technical standpoint, not to mention that actual operations themselves.
With something like Ottawa, sure that's been a complete mess, but at least in Ottawa it consistently uses ATO throughout the entire length of the line: at no point do operators need to switch signalling systems and start manually operating the train. Its relatively easy to design one or the other, it's not easy to make both.
P.S: I actually want to bring in another system that faced a similar problem recently, that being Crossrail in London. There, they had to come up with a system where trains would transition from being mainline trains operating with standard mainline operations and signalling, to metro like operations and signalling that can handle 90s headways in the tunnels. Decoding the signalling for that delayed the project by 18 months.
We're basically asking Eglinton to do the same thing, except now we're dealing with tram street side operations.