Yes. There are many people who will quite happily use a train, but wouldn't even consider taking a bus. I'd place a bet that 90% of my street have never used a local bus service.
I lived for a while in Loughton, on the Essex-London border. In the ~2 years I was there I took a TfL bus innumerable times, I took a non-TfL bus once one way (to Epping hospital, on the way back I walked to Epping station and got the tube as I wasn't constrained for time).
The reason for the discrepancy was that with the TfL services I knew the exact amount a single ticket would cost me, didn't need to faff with change (let alone exact change like some operators), I knew the routes and route numbers had been stable for years and wouldn't change in the future without significant publicity and I knew the buses were guaranteed to be roadworthy and almost always in good condition.
Not a single one of those was true for the Essex buses (although not roadworthy would be an exaggeration, several buses were barely so). This colours people's perceptions of buses. In London I happily use buses without a second thought. Outside London even finding the cost of a single ticket from A to B is night on impossible in some places (most recent example, Luton). If I have to use a bus elsewhere in the country I will get a plus bus if I can, as while it might not be cheapest it's by far the simplest and I don't need to worry about which operator accepts which tickets on which routes.
I have once used buses on the IoW but it was in 1996 and experience of buses elsewhere in the country tells me that buses everywhere but London have got significantly worse since then. In 1996 our journey (from Sandown to the Needles) required a change in Newport that involved changing bus stops from one street to another with almost no helpful signage in place. I don't know if this is true for the island, but tourists will use their experience of mainland buses and opt for the train, which their experience will tell them is more spacious, better maintained, more reliable and significantly simpler.