They need to be scrapped, period. If one's religion is vulnerable to mere words then that person truly is not a believer.
In principle, I agree with you, but once you ignore the reality on the ground, by that I mean the cultural sensitivities and requirements of a society, you ask for trouble, and you land yourself in more mess then you started with.
For instance, in Britain blasphemy laws still exist and are enforceable, but they only cover Christianity and Jewish religions, no ne else, as those were the predominant religions when the blasphemy law came into being. Muslims tried to use them during the Satanic verses episode, but they were not successful, because it did not cover Islam.
Those laws have become ineffectual because the society has changed over time, and, it is not longer a sensitive issue. Obviously once it was, otherwise, those law would not have been introduced.
In India, they forced secularism down people throats, but it was not, and is not suited to that society. That forced environment built support for the RSS and other Hindu organisations, and gave birth to the rise of BJP, because in essence Indian society is very conservative, with Hindu values.
So, if we fail to taken into account ground realities, there will be other problems. Having these laws is fine, that is not the issue, it is there implementation, that's the issue. Plus there are no legal ramifications for those who make false allegations, if people knew that they will be in trouble for making false allegations, things would improve.
Obviously a proper holistic approach that looks at the short comings of these laws is the best approach, not just the issues I mentioned. But to get rid of them would open a whole new can of worms. I think it is always better to move in balance, rather then take one side or the other.