So basically, you are saying that people were not allowed to protest Obama because in your opinion he had sound ideas, and then you follow up by saying people have a right to protest Trump.
No, anyone had the right to protest Obama. There just wasn't a huge incentive
to protest him, because in the end he was and is a moderate. He didn't propose to deport millions of people, or ban immigrants based solely on their religion. He didn't grope women, childishly insult them or threaten to "punish" them for taking advantage of reproductive freedom. He was neither a warmonger nor a diehard peacenik; even his health care plan was born out of compromise (if you want an
actual left-wing solution, it'd be single-payer).
Were there things you could get angry about if you were on the right wing? Sure. But enough legitimate gripes that hundreds of thousands of people would be marching on the streets? Not really. Unless you were part of that "Obama's a secret Muslim comin' to take our guns" camp, you weren't frightened for the future of the country.
That's not the case with Trump. His explicitly outlined policies and statements have minorities and women sincerely scared about losing the freedom and relative safety they've enjoyed under Obama. I see women rushing to get IUDs because Trump might take away their easy access to birth control; I see LGBT people rushing to get married or get passports because they're concerned future attempts will be delegitimized; I see minorities (including my brother's wife) terrified that equality efforts will stop or reverse, and that racists now feel free to show their hate in the open (we already have firm evidence of this happening).
Combine that with his fondness for torture, his coziness with Russia and his likely corrupt cabinet (a bank exec for the Treasury, an oil tycoon for the Interior, a creationist for Education and generally reviled old-guard politicians in other spots) and it's not surprising that there are protests. It's like all the effort Obama spent on compassionate, intelligent, moderate government just got swept away.