They dont have a horrific balance sheet, their margins were just under 10% last year, I think it was around 9.6%, they are consistently a Dividend Aristocrat, which if your a boring safe investor and invest for dividends, that is on the top of your list of things that you want to check off. I'm an investor in BCE stock I know what their financials look like because it affects my retirement plans (as would anyone who looks at their public financial disclosures). Bell took out a significant amount of loans to finance Fibe expansion, at the time with low interest rates, a duopoly in Telecommunications in Canada and CRTC "protection" it made perfect sense to do this. Recently two things happened that were not entirely predictable, interest rates rose to levels not seen in recent memory, putting pressure on Bell to service their debt at a much higher interest rate than was planned (I've heard rumors their interest payments are in the billions, which I doubt - again just a rumor, not substantiated by any reliable source), plus the CRTC has recently come out with multiple decisions that undercut Bells bottom line and their expected high returns with their expanded footprint. As a result of the CRTC decisions and margins dropping, Bell is making a transition from being a TelCo to being a TechCo. To do this they need to divest from TelCo products (Entertainment (MLSE) would be one of these products - dont be surprised if Bell sells off Bell Media sometime in the near future (TSN, CTV, Noovo, etc.) - just a gut feel for me TBH, this MLSE sale allows them to service their debt which investors love AND invest in high margin Tech Companies which investors love, that will have products that will help Bell transition to a TechCo. Bell is heavily invested in AI already, this sale TBH was a very very smart and needed and predictable move for BCE.
There is a universe of difference between a horrific balance sheet and transitional high debt due to investments.