The thing is, sports clubs aren't really businesses. A business' main aim is to turn a profit. A sports club's main aim is to produce on the field. A profit is nice, but it's not the main objectives. The most successful sports sides usually aren't the most successful business models by any stretch.
That's only true to a point.
Yes, the main aim for a sports club is on field production.
But everything they need for that, sooner or later, costs money.
Which means you really x 10000000 want a business as well.
You don't have to have one. Subsidies from various sources can substitute. But even in those circumstances, you still want a combination of the two and you still want that business side to be as strong as possible. The more money a club receives, the more it can invest in players, in facilities, in staff and so on. And increasingly, the clubs with good business models are dominating. Not always, but off field resources count heavily in sporting success, and barring serious subsidy that means good business models.
Which brings us to stadiums. There are four main sources of income available to a rugby club; tickets, merchandise, tv and competition monies, and sponsorship. A club that owns its own stadium has a fifth; renting out the stadium for non match-day purposes. Corporate hospitality, parties, weddings - I've heard of people doing law exams at Selhurst Park - anything - anything that makes a profit. It's a very worthwhile income stream and long term, clubs with their own stadiums will outstrip those without all other factors being equal. If Ospreys and Cardiff can't make money that way, it is that bit more an uphill struggle. The Welsh Regions' big problem is they don't even have the money to compete equally at the Pro 12 table, nevermind the European one, and that lack of success only leads to less money. It's a vicious circle and something big is needed to jolt it. The obvious solution is WRU funding but they clearly don't want to give it unless they control everything.
Which might work out ok. I'd point out that Ulster's recent revival has been hugely about what's been done off the pitch - Humphreys has done nothing on the coaching field but witness the ripples caused by his move - and Ulster is of course, union run. Up until Humphreys and Logan that did however mean blazers, of which I've heard little good. It's telling that Humphreys and Logan have business experience outside of rugby and you'd hope that the WRU would follow a similar model. Because at the end of the day, it doesn't matter which body precisely is at the top as long as they send competent people in to do the stuff at the sharp end.