In principle you are right, but here lies the problem. Uefa's opening position on ffp was that, to create a level playing field in a sporting sense, there had to be financial regulation to stop big clubs riding roughshod over smaller ones. It could be argued that ANY such regulation would ultimately be deemed to be anti competitive by ECJ.One of the fundamental problems you've identified is that UEFA is both a regulatory/governing body and a market competitor to those it regulates/governs. It competes with European clubs for sponsorship and refuses to allow sponsors of clubs, which are not sponsors of UEFA's champions league any access either live or televised on match nights. This clearly undermines the idea objective governance and, I think, should preclude UEFA from any role in the regulation of football finance. It raises the risk of corruption. I think the ECJ would rule it out but this alliance of brigands between the G14 and UEFA keeps it in place - but, I also think the ECJ would have no truck with trying to outlaw debt to finance player purchase because it is yet another attempt to limit investment. Staffing is something that companies in every sector take more seriously than anything else and in no sector would they accept being told that they could not appoint (buy) the staff they want because he/she costs too much. It doesn't matter if you're an SME on the High street or the Bank of England ....and it shouldn't matter if you're Manchester City.
The only way round that would be a voluntary agreement that clubs would not challenge ffp in court, which is really what has happened up to now, with the exception of the Belgian case. In that case the local courts and ECJ, just batted it back and forth between them with to a point where no real decision was ever made. And here we are..........