It's a ridiculous thing to argue anyway. MAN and LPL both have marketing and route planning folks who if they are doing their job properly will be sniffing around every airline that could conceivably dump a set of Dunlops on the local tarmac.
To the case in point, Wizz are an increasingly large airline, and MAN would be inept not to go sniffing round them, just as Wizz's route planning department would be inept not to assess the business case of flying from MAN on a regular basis. The circumstances when they first started flying to the UK were such that MAN weren't interested in locost, which may have been to LPL's benefit at the time, but as time has gone on clearly the cost case of sticking with LPL (and later DSA) rather than decamping to MAN has continued to be justified.
While MOL makes a lot of noise about how much airports charge to operate, the reality is that that cost is a small portion of the overall analysis of whether to operate a route. It would be irrelevant if MAN offered deals for free if the airline then couldn't fill the seats at a profitable level!
I would imagine it will become clear in the next 5 years if Wizz grow as expected whether they intend to remain away from EZY/RYR strongholds, and grow at smaller airports instead, or if they decide to take on the big 2 at bigger airports. Strategy 1 would be to the benefit of LPL/DSA; strategy 2 may not be.
At the risk of sounding like a stuck record - airports and airlines aren't charities, nor do they operate to keep local spotters entertained!