[t0astbread]

For a mass-market client, yes. But in an ideal world there would be alternatives that don't aim for market domination catered to a more advanced user base. Those could include functionality that would be unsafe for users who don't know exactly how it works.

[zaarn]

Well, that is what extensions are for in Thunderbird. As long as atleast one poweruser is willing, they can write the powertools.