Not only did it give too much representation to small and often politically extreme parties, but it also created too much political schism within the Reichstag, which made it very difficult for it to work together to pass laws (that's why Ebert used Article 48 so many times). Although this is a much more democratic electoral system than, for example, the UK's first-past-the-post system, the use of proportional representation meant that popularly elected parties were not effectively able to work for the betterment of their constituents, due to the country's fragmented and fragile political climate.