I agree, and since I don't think people really understand the voucher program, I'll try to explain that better (and why I will not blame any Catholic school that chooses to go that route and accept the vouchers ... which they all do).
The state originally put it in place to include only students who lived in the Cleveland Municipal School District, when it was the lowest performing district in Ohio, regardless of income level (Cleveland Scholarship). That allowed any family living with the CMSD boundary to receive a voucher (it's now up to $7,500) to use toward a private education (students meeting income guidelines would receive additional aid on top of that). But the vouchers weren't set up to specifically steer those students toward Catholic schools, rather all the fly-by-night, private (for profit) start-up charter/community schools that were popping up (in vacant churches/schools; empty storefronts at a mall/shopping center, etc.)
That Cleveland Scholarship program then was extended to include all the big city districts and then later some low performing suburban ones (some, such as Parma, have been since removed, and others added). Any family in a district that qualifies for the Cleveland Scholarship can get that scholarship regardless of income, so yes, there are millionaires who live on lakefront properties in places such as Edgewater or Bratenahl who are getting that $7,500, even though their children never have been enrolled at a Cleveland public school.
The program was then expanded to include lower income students at any school district in Ohio, regardless of whether the public district was struggling. That has further opened up students to leave public schools for privates (you can get a list of how many students have done so by viewing the district's state report cards on the Ohio Department of Education's website). I'll use Strongsville as an example (a district that is high performing and has low poverty). Strongsville now has roughly 350 students out of 5,300 (over 6 percent) who have left the district due to vouchers – 240 to charter/community schools; 50 through EdChoice expansion (likely a nearby Catholic schools such as Holy Name/Padua/Ed's/Ignatius); and 60 through a special needs voucher through the EdChoice expansion program (I'm not sure where those students end up).
The expansion of the voucher program, which originally only affected the big city districts (and those ones are still staggering if you look at how many students they lose due to the programs), are now starting to affect every district, especially ones in bigger metro areas where there are dozens of community/charter schools and several Catholic/religious schools nearby.
The EdChoice expansion program has been a boon to Catholic schools who now can draw lower-income students even from more affluent districts. I won't doubt that the program has made the gap wider between publics and privates in athletics. With that, these voucher programs have been supported and pushed for by the state government (through lobbying by "educators" looking to line their pockets by starting for profit charter/community schools). The long-standing Catholic schools happened to also be a benefactor. But the issue isn't with the Catholic schools but with the state government, which has set up this system to funnel students to various private schools at the expense of the public districts (who foot the bill for the voucher money). So, IMO, if anybody has an issue with the program, they should take it up with their representatives at the state level and not blame the Catholic schools who have benefited from it from both an athletic and enrollment standopoint.
Edit: FWIW, here is the link to where I got the numbers for Strongsville. You can look up any district by viewing their "district details" link on the state report cards and scroll to the bottom.
reportcard.education.ohio.gov