Oh it might - and should. However your question was just why would they vote Tory, not specifically for the Tories under Johnson. If you're asking for the reasons why people would vote for a Conservative party still led by Johnson (which I guess it would be if the election was tomorrow), then...
Never voted Tory in my life, but trying to look at it from their point of view I guess they would say that Johnson isn't the Tory party, and with a decent leader ('decent' as both a politician and a person) and a return to traditional 'one nation' Conservative principles a Conservative...