You-know-who was originally not a blood supremacist, and just generically evil. So was he evil to pure-bloods? ( not counting blood traitors). Asking partially because in cursed child Draco said that his father had preferred a world without Voldemort.
Some pure-bloods thought he went too far.
Many pure-bloods supported the Dark Lord, but as Sirius tells Harry, there were some pure-bloods who weren’t blood traitors and thought the Dark Lord had the right idea, but who didn’t like what he was willing to do to get power.
“Come on, Harry, haven’t you seen enough of this house to tell what kind of wizards my family were?’ said Sirius testily.
‘Were – were your parents Death Eaters as well?’
‘No, no, but believe me, they thought Voldemort had the right idea, they were all for the purification of the wizarding race, getting rid of Muggle-borns and having pure-bloods in charge. They weren’t alone, either, there were quite a few people, before Voldemort showed his true colours, who thought he had the right idea about things … they got cold feet when they saw what he was prepared to do to get power, though. But I bet my parents thought Regulus was a right little hero for joining up at first.”
- Harry Potter and the Order of the Phoenix, Chapter 6 (The Noble and Most Ancient House of Black)
There were, therefore, several pure-bloods who weren’t blood traitors but who didn’t support the Dark Lord.
The Dark Lord tried to spare pure-bloods.
Though the Dark Lord was certainly willing to kill, he didn’t kill pure-bloods if he could avoid it. He usually gives pure-bloods who oppose him a chance to join him instead. Despite Neville Longbottom’s clear resistance to him, he still offers Neville a chance to join the Death Eaters, he doesn’t just kill him.
“But you are a pure-blood, aren’t you, my brave boy?’ Voldemort asked Neville, who stood facing him, his empty hands curled in fists.
‘So what if I am?’ said Neville loudly.
‘You show spirit, and bravery, and you come of noble stock. You will make a very valuable Death Eater. We need your kind, Neville Longbottom.”
- Harry Potter and the Deathly Hallows, Chapter 36 (The Flaw in the Plan)
The Death Eaters also avoided killing pure-bloods. Neville told Harry he knew that the members of Dumbledore’s Army were fairly safe because the Death Eaters didn’t want to spill too much pure blood.
“Neville shrugged. ‘Doesn’t matter. They don’t want to spill too much pure blood, so they’ll torture us a bit if we’re mouthy but they won’t actually kill us.”
- Harry Potter and the Deathly Hallows, Chapter 29 (The Lost Diadem)
The Dark Lord was also willing to spare the lives of wizards who weren’t pure-blood. At Hogwarts, he offered all those fighting him a chance to join him, and said that every drop of magical blood spilled is a waste. He offered mercy to all except Mudbloods.
“You have fought,’ said the high, cold voice, ‘valiantly. Lord Voldemort knows how to value bravery.
‘Yet you have sustained heavy losses. If you continue to resist me, you will all die, one by one. I do not wish this to happen. Every drop of magical blood spilled is a loss and a waste.
‘Lord Voldemort is merciful. I command my forces to retreat, immediately.”
- Harry Potter and the Deathly Hallows, Chapter 33 (The Prince’s Tale)
The only blood statuses that the Dark Lord targeted were Mudbloods and blood traitors. Though he’d kill specific pure-bloods or half-bloods if necessary, he attempted to avoid it.