The entire reason that WN is not as big in CLE is because CLE was the last of the major hubs to be dehubbed. The only other dehubbed airport (that isn't still a focus city) that does not have WN as their dominant carrier or with significant operations is MEM, which is simply due to the lack of O&D traffic there.
Your evidence for that is what exactly? You furnish an example of correlation but not causation, unless you are privy to route planning discussion at WN. I don't buy it at all. The pattern I would observe is that CLE is boxed in by BWI/BNA/and MDW on all sides, and further, despite ample gate capacity today, CLE doesn't have daily WN service to DAL/HOU/LAS/or ANYWHERE in FL, unlike other larger cities surrounding CLE, just not a big station for WN never has been never will be. If anything, the pattern I would observe (and my example too is correlation but not causation) is that F9 was crazy aggressive in moving in after UA, followed pretty shortly by NK, and that shut the door on WN's willingness to open up some FL routes and to build their presence here. FL is really, really key to building loyalty, I think that's why UA keeps MCO, RSW, and FLL. WN has Florida service from other nearby cities. . .
And Southwest is not serving Burke, with all due respect to many of you I enjoy chatting with, that is simply not going to happen-- is this really meant to be a serious trial balloon on here? People complain about parking at Hopkins-- how the heck could Burke support 20-25 737s a day, plus rental car capacity, plus car drop off space, plus renovations for TSA/concessions and so forth (I've not been to Burke in a while but I can't imagine it can accommodate 6-7,000 arriving/departing pax per day in any of those dimensions I mention). I'll give you this, BKL certainly has takeoff and landing capacity, the place is a ghost town. Before BKL opens up to that operation there'd need to be all sorts of feasibility and ground transportation studies.