Wrong analogy imo, Saddam was keeping a lid until he was removed and the Iraqi state dismantled by the US, Assad on the other hand could not keep a lid forever on millions of people seething under his despotic rule. Supporting Assad will condemn Syrians to a long reign of Assad's sadistic security services and their torture dungeons and will inevitably mean a lot more refugees in the future. Also if you think Putin's appetite will stop in Syria you'd be mistaken, he's on a roll since Obama's red line was crossed.
You're watching too much Fox News Kool-Aid.
If Assad is such a tyrant, why is the Syrian Army keeping on fighting when it is in majority Sunni? (the answer is that Assad is the only guarantor of a secular Syria). If Assad persecutes minorities, why are some of his top generals Christians? Even the Syrian Army Colonel the RCMP seeks extradited for torturing Arar is a Christian.
People are fleeing Syria because ISIS is gaining more and more territory and the Syrian Army is exhausted. After 5 years of fighting, they see little hope of ever going back to their ISIS occupied homes again. Ask any Syrian living in Canada and they will tell you that Assad is their guy who kept this multi-confessional country peaceful.
The riots 5 years ago were the result of severe drought for the previous 5 years that resulted in a large proportion of rural area residents coming to cities. Then food prices went up and riots took place. Don't believe especially US mainstream media, as they are controlled by about 3 major US corporations. They toe the US policy line and even if their journalists ask their government embarrassing questions, that never appears in their news stories. The US news media routinely censors their news in order to fit the narrative and not appear unpatriotic. Being patriotic is not questioning the government line; US journalistic ethics and independence of Watergate and Viet-Nam era are dead; journalist jobs are few and not writing the right stuff gets you fired. Same thing happened to the run-up to the 2003 US invasion of Iraq under the pretext of WMD; no major news media questioned the narrative, except Knight-Ridder News Service.
The US is only interested in regime change because Assad is in the Russian camp and refuses to cow-tow to US foreign policy. With Assad out of the picture, any regime (including ISIS) replacing him is seen as beneficial to their goals: the establishment of a gas pipeline to carry Qatari and Saudi natural gas directly to Europe through Syria and Turkey. Saudi Arabia has another objective: as Assad is allied to Iran (so is Iraq BTW), it would eliminate Iranian influence over Iran friendly Iraq, Shiite controlled Syria and Shiite Hezbollah in Lebanon. They see Iranian influence over the largely Saudi-Shiite population in Eastern Saudi-Arabia , who Riyadh treats like dirt, as threatening. That's also why they're bombing Yemen back into the stone age: because they could not keep their puppet despot in Saana and the Shiite Houtis, who they suspect have Iranian backing, have popular support.
This is not about saving Syrians from oppression or harm. Its about US geopolitics (including reducing Russian influence) and Saudi dominance over the Middle East.