This article is possibly the laziest piece of journalism with no thoughts to any facts. All wireless providers need backhaul, wireless is never going to see the same speeds as line services. Telkom has the biggest physical line network and could keep it this way if they focussed on this. Instead they are trying to take the fight to the mobile operators and not get competitive on the line services.
It would make more long term sense to get the line network sorted, making their pricing too good to pass up therefore mobile operators would have no incentive to build their own fibre networks. Thus maintaining a monopoly by sheer scale and quality of service. They could also promote smaller ISPs and competition in the retail market by clever national access packages.
By trying to compete on all fronts they are not able to best use their capital or expertise and are essentially doing everything halfway. Mobile is going to see massive diminishing returns as competition forces them to change their models, so if I were Telkom I would stick to areas I could maintain dominance and profitability.