Dan Hesse obviously inherited a job that was left to him as a mess by his competitors. So, I really don't blame him for what was beyond the scope of what he could do to help Sprint. I don't even blame Marcelo Claure for Sprint's financial problems either. Mostly I like Claure, though I don't think he's as good a CEO of Sprint than Dan Hesse was (I'm not judging the CEO role of either of their capabilities in general, only in charge of Sprint). Although I have had some criticisms of Claure in the past, I've become more focused in my thinking of Softbank as Sprint's main problem.
I really don't know if Claure is responsible or not for the network delays, but looking at it like I have been lately, my guess is that Claure's only flaw in this is his reluctance to get help from Softbank. Sprint has lost alot of customers and sadly I have to agree with some of the anti-Sprint people who criticize Sprint for the free year of service offer, because it really isn't a good business decision to do. Better to offer free trial periods, say perhaps extending to 90-day trials with leased "loaner" devices to potential future customers who are unsure about the network quality, etc.
However, if Softbank were to have intervened by spending money on the network immediately after getting Sprint, they could have stopped the flow of churn with people leaving Sprint for network reasons, then with a strong Sprint in place, could have then focused on the spending cuts, etc and in making Sprint strong on its own. Sprint didn't need austerity right then, it needed massive funding. The lack of financial input on the network has lost Sprint customers over to T-Mobile and the non-uncarriers. Dan Hesse though with his spending plans may have worsened Sprint financially for a while, but would have turned Sprint's fortunes around later on.
Softbank didn't support that, didn't support that, didn't want to spend on Sprint, other than getting Sprint merged with T-Mobile. When that didn't happen at first, it made Masa sad, when all he had to do otherwise was to take the money he was prepared to use to buy T-Mobile during the early deal talks before DT gained so much confidence and support behind T-Mobile, and spend that money on Sprint. Imagine those billions of dollars behind massive macro tower site densification and all of that additional band 41 deployment. Sprint would be doing splendidly by now with that. Still, I think Marcelo probably really wants this too, just like Dan Hesse did, but its a matter of dealing with Softbank that is the issue.