Because the BBC have allowed a section of the community to be very vocal in their love for an averagely talented broadcaster.
Wogan has parlayed this into an amorphus mass of self-depricating arrogance which he pretends is him just being 'himself'.
This is patently a lie, since he has deveoped a fashion of delivery that is unheard by anyone on God's earth - at least since Jimmy Young was binned off.
The BBC has continued to partake in this marriage of dishonour, fosting him on the public ad nauseum until even his fans who live on a diet of sycophancy and liquid marzipan could stand it no longer and stopped tuning in.
He is thankfully on the last lap, and will soon take his humourless nonsense to a never-ending circuit of WI after-lunch engagements, and leave his slot for someone who is genuinly funny, knowledgable and definitely 'himself - Stewart Maconie.
And if they DARE give the job to that ageing terminally boring God-botherer Walker, I will be down to Broadcasting House with a large polo mallet!