IMO, the real issue about Plante's legacy is not whether she should have done this or not, but much more about how her administration did things.
1. Secure bike path for people who live in the city are great and have a lot of different benefit. In the last 5 years, bike traffic has increased by more than 20% a year.
The downside of her action are more about the crazy speed of implementation of the new network of path and their design or location. Some are well designed and nicely integrated in the city fabric but others are a total nonsence...
2. Dirty city, only the responsability of the administration? Not true. Each and evey one has the responsabilty of it. How we manage our garbage and we behave in the public space is everyone business. I still witness on a daily basis people throwing their cigarette butch on the sidewalk or sometime even emptying the car's ashtray on the street. Regularly I see dog poop bag left on the ground.. etc. Just travel in other country like Japan, you will notice almost no public garbage bin. Still it's one of the cleanest place in the world.
3. Traffic jam: Yes, too many constructions project at the same time, very poor management and way too long delays, stupid street traffic light system, no communication and go on..., almost engineered in my mind.
4. War to small businesses operators and restaurants: not enough support in term of bylaw for control of commercial property leases and for the serious impact of all the above...
I will stop there but the list of other things is long.... The city structure, with all the buroughs figthing the central, too much non efficient bureaucracy...
In all, Montreal is a difficult city to manage but it has its charm and can be a very nice place to live...