There are, of course, many people who would argue that this is actually a good development. They would point out that full-time legislators can become more knowledgeable. They would point out that full-time legislators are paid for their work and therefore do not have to be rich or to have the sorts of jobs that let them take a few months off to participate in the legislature. However, there are those who say that this is a bad thing.
The people who say this is a bad thing are generally conservative. They feel that government already does too much. They also feel that legislators lose touch with regular people and stop legislating in ways that are truly good for the state. To these people, full-time legislators are bad because they are likely to spend more time passing laws. The laws they pass will expand the reach of government farther and farther. This is a bad thing. Conservatives also argue that full-time legislators become wedded to the government and detached from their constituents. This makes them less responsive to the needs of the people.
For these reasons, many people would argue that it is bad to have full-time legislators.