Former Love Island contestant Dr Alex George said he had received online abuse and threats of violence after announcing his purchase of four Welsh holiday homes on social media.
He revealed his Pembrokeshire project on Instagram, inviting people to follow his "renovation journey".
Some voiced concerns that homes were being taken away from locals in an already squeezed housing market.
He said he hoped one of the homes would be offered to Ukrainian refugees.
Responding to criticism that he was reducing the already limited housing stock, the social media influencer said: "You can take my word for it or not, these cottages would not be possible for residential purchase."
Dr George, who is from neighbouring Carmarthenshire, added he had received threats and online abuse since posting about his purchase, saying this was "never acceptable".
Describing the houses as "relaxing spaces for families to holiday and enjoy the Welsh countryside," he suggested that three of them would be used for short-term rentals and the fourth for a Ukrainian family.
But in a promotional video, he said the homes were previously used as long-term lets, sparking an online debate.
One contributor described how "my generation is getting pushed out because we can't afford to live here".
Another said: "I am one of hundreds of families facing homelessness as there are so few properties left in the area to rent."
Last year, Pembrokeshire council's cabinet voted for second home owners to pay double the normal rate of council tax, saying it would help provide income to build more affordable homes.
More than 1,200 properties in Pembrokeshire have become second homes in three years, an increase of 45%.
'I live in a caravan'
Valerie Morris, 79, has lived in Pembrokeshire her whole life but with house prices so high, she lives in a static caravan in her daughter's garden.
It has two bedrooms and "not much house work", which she said suited her but she would prefer to have a cottage of her own.
"You see a house that should be lived in with a family and it's locked up and people pop down at the weekend," she said.
Cardiff-based journalism student Thomas Reynolds, 22, from Solva, said house prices in the Pembrokeshire community had "increased dramatically" in the past few years because of second homes.
"Local people struggle to live in the place where they grew up," he said.
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